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Landforms
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Shi'b
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A shi'b in Arabic is a "gorge" or "canyon" for a usually (stationary or temporary) dry river. Placenames using the word are common in the Arabic peninsula.
== Saudi Arabia ==
Shi‘b adh Dhi’b
Ash Shi`b
Shi`b `amir
== Yemen ==
Ash Shiʽb al-Aswad
Shiʽb an-Nur
Shiʿb Hūd
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Landforms
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Shutter ridge
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A shutter ridge is a ridge which has moved along a fault line, blocking or diverting drainage. Typically, a shutter ridge creates a valley corresponding to the alignment of the fault that produces it. Shutter ridges occur exclusively at strike-slip faults.
== Example Locations ==
Oakland, California
Dragon's Back, Carrizo Plain, CA
== References ==
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Landforms
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Siek (landform)
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Siek is a north German term for a wet depression, hollow or lowland area. It is mainly used to describe typical cultural landscape elements in eastern Westphalia, especially in the county of Lippe and in the region of Ravensberg Land. In East Westphalia "siek" is a very common component of the names of tracts of land, roads, places and even personal names, e.g. Heidsiek, Siekhorst, Im Siek, Siekmann and Sieker.
== Origins ==
The fertile loess soils in this region of north Germany are dissected by a host of brooks and headstreams, which used to flow in marshy V-shaped valleys. Not all Sieke are or were, however, crossed by a stream, but at the very least they always consisted of wet ground. During the course of medieval and early modern cultural and agricultural history, people developed these natural landforms by cutting into the edges of the V-shaped valleys (so-called Wiesenbrechen by Wiskenmaker) and turning them into trough and box valleys, and any streams were regulated such that they ran in straight beds along the edges of such a box valley. The aim of these measures was the create a wet grassland in the now broad, accessible stream meadows which could then be extensively cultivated. In addition the cut, grass sods or plaggen were able to be used to fertilise the surrounding fields (Plaggendüngung). In Ravensberg Land, sieke are generally narrow, trough valleys interspersed in the countryside and lying next to cultivated areas of slightly higher ground or kuppen (Plaggenesche), which were raised by the grass sod fertilisation.
== Importance today ==
Since, owing to the changed production conditions in modern agriculture, the grasslands in the sieken have become economically largely superfluous, many unused sieke would become marshy again in the long term without mowing and maintenance and turn into black alder carrs. Conservation and cultural landscape management today have the task of ensuring a balanced relationship between renaturalising sieken on the one hand and regularly mown grassland sieken on the other. An example of protected siek systems is the Kilverbach valley (52.228667°N 8.461318°E / 52.228667; 8.461318 (Kilverbachsiek)) and the Wöhrener Siek in Ravensberg Land.
== Siepen ==
Etymologically probably related and conceptually similar is the valley landform known as asiepen, which is mainly found in the south Westphalian area and generally also describes wet valley bottoms, mostly stream-bearing V-shaped valleys.
== References ==
== Literature ==
Florian Herzig: Vom Wert der feuchten Wiesen, Entstehung, Nutzung und Zerstörung der Sieke im Ravensberger Hügelland. In: Kreisheimatverein Herford (publ.), Kommunalarchiv Herford (publ.): Historisches Jahrbuch für den Kreis Herford 2005. Verlag für Regionalgeschichte. Bielefeld, 2004. ISBN 389534592X
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Landforms
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Sky island
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Sky islands are isolated mountains surrounded by radically different lowland environments. The term originally referred to those found on the Mexican Plateau, and has extended to similarly isolated high-elevation forests. The isolation has significant implications for these natural habitats. The American Southwest region began warming up between c. 20,000 and 10,000 years BP and atmospheric temperatures increased substantially, resulting in the formation of vast deserts that isolated the sky islands. Endemism, altitudinal migration, and relict populations are some of the natural phenomena to be found on sky islands.
The complex dynamics of species richness on sky islands draws attention from the discipline of biogeography, and likewise the biodiversity is of concern to conservation biology. One of the key elements of a sky island is separation by physical distance from the other mountain ranges, resulting in a habitat island, such as a forest surrounded by desert.
Some sky islands serve as refugia for boreal species stranded by warming climates since the last glacial period. In other cases, localized populations of plants and animals tend towards speciation, similar to oceanic islands such as the Galápagos Islands of Ecuador.
== Etymology ==
Herpetologist Edward H. Taylor presented the concept of "Islands" on the Mexican Plateau in 1940 at the 8th American Scientific Congress in Washington, D. C. His abstract on the topic was published in 1942.The sky island concept was later applied in 1943 when Natt N. Dodge, in an article in Arizona Highways magazine, referred to the Chiricahua Mountains in southeastern Arizona as a "mountain island in a desert sea".In about the same era, the term was used to refer to high alpine, unglaciated, ancient topographic landform surfaces on the crest of the Sierra Nevada, California.The term was popularized by nature writer Weldon Heald, a resident of southeastern Arizona. In his 1967 book, Sky Island, he demonstrated the concept by describing a drive from the town of Rodeo, New Mexico, in the western Chihuahuan desert, to a peak in the Chiricahua Mountains, 56 km (35 mi) away and 1,700 m (5,600 ft) higher in elevation, ascending from the hot, arid desert, to grasslands, then to oak-pine woodland, pine forest, and finally to spruce-fir-aspen forest. His book mentions the concept of biome, but prefers the terminology of life zones, and makes reference to the work of Clinton Hart Merriam. The book also describes the wildlife and living conditions of the Chiricahuas.Around the same time, the idea of mountains as islands of habitat took hold with scientists and has been used by such popular writers as David Quammen and John McPhee. This concept falls within the study of island biogeography. It is not limited to mountains in southwestern North America but can be applied to mountains, highlands, and massifs around the world.
== Characteristics ==
The Madrean sky islands are probably the most studied sky islands in the world. Found in the U.S. states of New Mexico and Arizona and the Mexican states of Chihuahua and Sonora, these numerous mountains form links in a chain connecting the northern end of the Sierra Madre Occidental and the southern Colorado Plateau. Sky islands of the central and northern mountains in the United States are often called island ranges, especially by populations within view of such islands of mountains surrounded by plains such as those found within the Wichita Mountains of southwestern Oklahoma.
Some more northerly examples are the Crazy Mountains, Castle Mountains, Bears Paw Mountains, Highwood Mountains, and Little Rocky Mountains, all in the US state of Montana. Each of these ranges is forested and has tundra and snowpack above treeline, but is not connected to any other range by forested ridges; the ranges are completely surrounded by treeless prairie and/or semi-arid scrubland below. Other well-known sky islands of North America are the Great Basin montane forests, such as the White Mountains in California, and the Spring Mountains near Las Vegas, Nevada. One of the unique aspects of the sky islands of the U.S.-Mexico border region is the mix of floristic affinities, that is, the trees and plants of higher elevations are more characteristic of northern latitudes, while the flora of the lower elevations has ties to the desert and the mountains further south. Some unique plants and animals are found in these sky islands, such as the mountain yucca, Mount Graham red squirrel, Huachuca springsnail, and Jemez Mountains salamander.
Some montane species apparently evolved within their current range, adapting to their local environment, such as the Mount Lyell shrew. However, it has also been noted that some isolated mountain ecosystems have a tendency to lose species over time, perhaps because small, insularized populations are vulnerable to the forces of extinction, and the isolation of the habitat reduces the possibility of colonization by new species. Furthermore, some species, such as the grizzly bear, require a range of habitats. These bears historically made use of the forests and meadows found in the Madrean sky islands, as well as lower-elevation habitats such as riparian zones. (Grizzlies were extirpated from the region in the 20th century.) Seasonal movements between highland and lowland habitats can be a kind of migration, such as that undertaken by the mountain quail of the Great Basin mountains. These birds live in high elevations when free of snow, and instead of migrating south for the winter, they migrate down.Confusing the matter somewhat is the potential for an archipelago of sky islands or even the valleys between them to act not only as a barrier to biological dispersal, but also as a path for migration. Examples of birds and mammals making use of the Madrean archipelago to extend their ranges northward are the elegant trogon and white-nosed coati.
== List by terrestrial realms ==
=== Afrotropical realm ===
Cal Madow
Cameroonian Highlands forests
Ethiopian Highlands
Highlands of southern Africa
Green Mountain of Ascension Island
Guinea Highlands
Nimba Range
Mount Cameroon and Bioko montane forests
Mount Kilimanjaro
Mount Gorongosa
Rwenzori Mountains
=== Australasian realm ===
Mount Wilhelm
Mount Taranaki
Waitakere Ranges
=== Indomalayan realm ===
Mount Jerai
Fansipan
Jade Mountain
Mount Kinabalu
Nat Ma Taung
Central Highlands (Vietnam)
Titiwangsa Mountains
Western Ghats
=== Nearctic realm ===
Animas Mountains
Black Range
Capitan Mountains
Chisos Mountains
Colorado Plateau's San Francisco Peaks
Chuska Mountains
Great Basin montane forests
Davis Mountains
Guadalupe Mountains
San Jacinto Mountains
Madrean sky islands
Manzano Mountains
Mogollon Mountains
Oscura Mountains
Olympic Mountains
Peloncillo Mountains
Quartz Mountains
Sacramento Mountains
San Augustin Mountains
Sandia Mountains
Spring Mountains
Mount Taylor Volcano
Wichita Mountains
=== Neotropical realm ===
Baja California
Sierra de la Laguna
Sierra de Juarez
Sierra San Pedro Mártir
Cordillera of Central America
Tepuis
Serra do Mar
Hispaniolan mountain ranges
Baoruco Mountain Range, Dominican Republic
Cordillera Central, Dominican Republic
Massif de la Hotte, Haiti
Chaîne de la Selle, Haiti
Sierra de Tamaulipas
Venezuelan Coastal Range
=== Palearctic realm ===
Aïr Mountains
Altai Mountains
Baikal Mountains
Caucasus
Tibesti Mountains
Tien Shan
== See also ==
Altitudinal zonation
Life zone
Holdridge life zones
Inselberg or monadnock
List of life zones by region
Refugium (population biology)
Table (landform)
Tepui
== References ==
== External links ==
Sky Island Alliance homepage
Sky Islands Traverse long-distance hiking route
Saguaro-Juniper Corp. webpage
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Landforms
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Slot canyon
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A slot canyon is a long, narrow channel or drainageway with sheer rock walls that are typically eroded into either sandstone or other sedimentary rock. A slot canyon has depth-to-width ratios that typically exceed 10:1 over most of its length and can approach 100:1. The term is especially used in the semiarid southwestern United States and particularly the Colorado Plateau. Slot canyons are subject to flash flooding and commonly contain unique ecological communities that are distinct from the adjacent, drier uplands. Some slot canyons can measure less than 1 metre (3 ft) across at the top but drop more than 30 metres (100 ft) to the floor of the canyon.
Many slot canyons are formed in sandstone and limestone rock, although slot canyons in other rock types such as granite and basalt are possible. Even in sandstone and limestone, only a very small number of streams will form slot canyons due to a combination of the particular characteristics of the rock and regional rainfall.
== Around the world ==
Slot canyons are found in many parts of the world, predominantly in areas with low rainfall. Some of the best-known slot canyons are to be found in the Southwestern United States. Other significant areas include the Sierra de Guara in northern Spain, the Pyrenees on the border of France and Spain, and the Blue Mountains in New South Wales, Australia.
=== Australia ===
The largest known area of slot canyons in Australia (containing over 900) is in the Blue Mountains, west of Sydney. They occur in a narrow band of sandstone that runs roughly 30 kilometres (19 mi) from east to west, and about 100 kilometres (62 mi) from south to north. The majority of these canyons are in the Wollemi Wilderness, and are difficult to access. Many canyons within the Wollemi Wilderness have yet to be explored by humans. A small number are regularly visited by canyoners on weekends in summer with those closest to Katoomba being the most frequently visited. The Grand Canyon, near Blackheath, has a tourist track along its rim, but requires abseiling (rappelling) or swimming to visit fully.
Sandstone slot canyons can also be found in a few more remote parts of Australia, including Karijini National Park and the Bungle Bungles in Purnululu National Park, both in Western Australia, and Carnarvon Gorge in Queensland.
=== United States ===
Southern Utah has the densest population of slot canyons in the world with over one thousand slot canyons in the desert lands south of Interstate 70. Utah's slot canyons are found in Zion National Park at The Narrows, along Canyonlands National Park's Joint Trail, throughout Capitol Reef National Park, within the San Rafael Swell and the Grand Staircase–Escalante National Monument, especially along the Escalante River drainage including Coyote Gulch. Many more slot canyons are located on public Bureau of Land Management and state-owned lands in southern Utah, in areas surrounding the aforementioned parks and monuments. Buckskin Gulch—one of the longest slot canyons in the world—begins in southern Utah and continues into northern Arizona within the Paria Canyon-Vermilion Cliffs Wilderness. Northern Arizona also has a high concentration of slot canyons including Antelope Canyon and Secret Canyon, which are two of the most famous slot canyons located near Page on land owned by the Navajo Nation. Slot canyons are also located in the valley between U.S. Route 89 and the Vermilion Cliffs in Arizona, and can be seen as one descends into the valley on U.S. 89, but these are on the Navajo reservation and are closed to the public. The Kasha-Katuwe Tent Rocks National Monument's slot canyon trail in New Mexico is unique as it was carved into tuff (volcanic ash). In California, several slot canyons are located within Death Valley National Park.
=== Europe ===
There are a number of slot canyons in Spain, especially in the arid foothills of the Pyrenees, such as on the Balcez river. There is an extensive tourism industry built around canyoning in this region. In Czechia, there is a spectacular slot canyon in the Teplice Mountains called Little Siberia due to the microclimate, which is several degrees colder than the surrounding area. The canyons in Teplice are surrounded by pillar-like rock formations which resemble various animals and were the site where The Chronicles of Narnia were filmed.
== Drowning danger ==
Local as well as distant storms can cause dangerous flash flooding in slot canyons, and hikers should not enter them if there is any sign of rain in the surrounding area. In many slot canyons, it can be miles before a safe exit or rescue is possible.
Australia's Blue Mountains in particular have claimed the lives of several often due to flash flooding.On August 12, 1997, eleven tourists, seven from France, one from the United Kingdom, one from Sweden and two from the United States, were killed in Lower Antelope Canyon by a flash flood. Very little rain fell at the site that day, but an earlier thunderstorm had dumped a large amount of water into the canyon basin, seven miles upstream. The lone survivor of the flood was tour guide Francisco "Poncho" Quintana, who had prior swift-water training. At the time, the ladder system consisted of amateur-built wood ladders that were swept away by the flash flood. Today, ladder systems have been bolted in place, and deployable cargo nets are installed at the top of the canyon. A NOAA Weather Radio from the National Weather Service and an alarm horn are stationed at the fee booth.On July 15, 2021, a Michigan woman died in a flash flood that swept through a slot canyon in Grand Canyon National Park. She was a customer with a commercial rafting group that camped overnight about a quarter of a mile from a slot canyon. Five other people with serious injuries were airlifted from the canyon as a result of the same flash flood.
== Gallery ==
== See also ==
One-Line Sky
== References ==
== External links ==
Media related to Slot canyons at Wikimedia Commons
Southern Utah's Slot Canyons
Slot Canyons of the American Southwest
Video walk-through of a very tight slot canyon
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Landforms
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Snow field
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A snow field, snowfield or neve is an accumulation of permanent snow and ice, typically found above the snow line, normally in mountainous and glacial terrain.Glaciers originate in snowfields. The lower end of a glacier is usually free from snow and névé in summer. In the upper end and above the upper boundary of a glacier, the snow field is an ice field covered with snow. The glacier upper boundary, where it emerges from under a snow field, is ill-defined because of gradual transition.
== References ==
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Landforms
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Sods
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Sods is a term used in the Allegheny Mountains of eastern West Virginia for a mountain top meadow or bog, in an area that is otherwise generally forested. The term is similar (perhaps identical) to that of a "grass bald", a more widespread designation applied throughout the central and southern Appalachian region.
The best known example of a sods is Dolly Sods, a federally designated wilderness area in Tucker County, West Virginia and popular destination for recreationalists. Other examples include Nelson Sods (Pendleton County) and Baker Sods (Randolph County).
== Ecology ==
West Virginia University botanist Earl L. Core addressed the origin of the "sods" in 1973:
How did it happen that these grassy tracts were originally [prior to white settlement] treeless, when all the surrounding areas were covered with trees? No one really knows. Although the "sods" and "balds" have been the subject of much speculation, discussion, and research, no generally-accepted explanation has yet been proposed for their existence. Perhaps there is not really any one cause; the treelessness may be the result of a complex situation which may vary from place to place. Factors suggested may be classified as natural or artificial. Among the natural have been listed climatic, edaphic (soil), topographic, biotic and pyric (fire).
The dominant grass is Allegheny flyback (danthonia compressa), a grass so light in weight that it would "fly back" against the scythe of the mower.
== See also ==
Appalachian bogs
== References ==
== Further reading ==
Core, Earl L. (1949), "Original Treeless Areas in West Virginia", J. Elisha Mitchell Sci. Soc., 65:306-310.
Rentch, James S. and Ronald H. Fortney (1997), “The Vegetation of West Virginia Grass Bald Communities”, Castanea, 62(3): 147-160 (September issue).
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Landforms
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Spur (topography)
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A spur is a lateral ridge or tongue of land descending from a hill, mountain or main crest of a ridge. It can also be defined as another hill or mountain range which projects in a lateral direction from a main hill or mountain range.Examples of spurs include:
Abbott Spur, which separates the lower ends of Rutgers Glacier and Allison Glacier on the west side of the Royal Society Range in Victoria Land, Antarctica
Boott Spur, a subpeak of Mount Washington
Kaweah Peaks Ridge, a spur of the Great Western Divide, a sub-range of California's Sierra Nevada
Kelley Spur, four kilometres (two nautical miles) east of Spear Spur on the south side of Dufek Massif in the Pensacola Mountains, Antarctica
Geneva Spur on Mount Everest
Sperrin Mountains in Northern Ireland
== See also ==
Draw or re-entrant, the low ground between two spurs
Spur castle
== References ==
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Landforms
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Steilhang
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A Steilhang (pl: Steilhänge) is a geoscientific term for a steep mountainside or hillside (or a part thereof), the average slope of which is greater than 1:2 or 30°. Leser defines a steilhang as a mountainside with an incline of between 16° and 60°, slopes of between 30° and 60° being described as "very steep" (übersteil) and anything over 60° being a rock face (wand).The term is German for "steep slope/mountainside/hillside", "escarpment" or "steep face". The word hang in this compound is derived from hängen, "to hang". Also compare the British English word hanger (from Old English hangra) for a steep wooded slope (compare Hanger Lane), or used to mean woods on steep hillsides, e.g. for the East Hampshire Hangers.
== Geology ==
The formation of slopes of different gradients depends on the one hand on the type of underlying rock of the mountain or hill - and this may result in slopes varying from those on the other side of a mountain, hill or valley – and on the other hand on its local hardness, and circumstances of its deposition (sedimentation, stratigraphy, bedding or jointing), on its resistance to erosion and not least on the water flow and local climatic conditions.
From a geomorphological standpoint, there is a distinction made between steilhänge not simply on the basis of their gradient and rock type, but especially on their aspect (i.e. their orientation), their rotundity or roughness (small shapes, flexion, steps, terraces, drainage etc.), the vegetation on the mountainsides or hillsides and the soil formation.
For example, the soil type known as ranker gets its name from the word Ranker which is commonly used in Western Austria to mean steilhang.
== Natural dangers ==
Steilhänge present various natural dangers if they are not forested or interrupted by gentler slopes:
Landslides – especially if the soil is saturated after long periods of rain or during snowmelt
Collapse – if there is a rock face or heavily eroded crags above, or
Rockfall, a less severe occurrence
Destruction caused by mudflows during bad weather or avalanches
episodic or sudden rock creep, that may threaten to impound water.
== Farming ==
Steilhänge of up to about 40° can in principle be used for farming – for example to make hay or in forestry to obtain wood. Under favourable climatic conditions they can even be used for viticulture. But they are only rarely economic when compared with more level landscapes with which they are in competition. As a result, hill farmers (their definition varies according to the location of the uplands and their hillsides) are usually supported from the public purse.
This support of the alpine forestry and agriculture is sometimes not only justified, but also essential. Traditionally the higher level authorities are responsible (especially the German states for example), because the individual municipalities are economically unable to. Geotechnological institutions from the fields of mining, avalanche protection and tourism, as well as the EU are active in supporting the affected highlands in Europe
Through sensible support, hill farmers are encouraged or enabled to continue to work their farms or alms. Where this does not happen, the damage caused by the aforementioned natural dangers is generally more costly over time than the costs of subsidising hill farming. The advantages of protective and support measures are:
Preservation of protected forests (especially against mudflows and avalanches)
General conservation ("hill farmers as landscape gardeners")
Environmental protection (e.g. preservation of soil quality, biodiversity, etc...)
Tourism (desire for "intact landscapes", native customs, etc.)
Control of mountain streams and avalanches
Protection of roads and stabilization of forest tracks
Increased self-sufficiency in terms of the local supply of food and raw materials
Regional aspects of planning.
== References ==
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Landforms
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Swale (landform)
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A swale is a shady spot, or a sunken or marshy place. In US usage in particular, it is a shallow channel with gently sloping sides. Such a swale may be either natural or human-made. Artificial swales are often infiltration basins, designed to manage water runoff, filter pollutants, and increase rainwater infiltration. Bioswales are swales that involve the inclusion of plants or vegetation in their construction, specifically.
== On land ==
The use of swales has been popularized as a rainwater-harvesting and soil-conservation strategy by Bill Mollison, David Holmgren, and other advocates of permaculture. In this context a swale is usually a water-harvesting ditch on contour, also called a contour bund.
Swales as used in permaculture are designed by permaculturalists to slow and capture runoff by spreading it horizontally across the landscape (along an elevation contour line), facilitating runoff infiltration into the soil. This archetypal form of swale is a dug-out, sloped, often grassed or reeded "ditch" or "lull" in the landform. One option involves piling the spoil onto a new bank on the still lower slope, in which case a bund or berm is formed, mitigating the natural (and often hardscape-increased) risks to slopes below and to any linked watercourse from flash flooding.
In arid and seasonally dry places, vegetation (existing or planted) in the swale benefits heavily from the concentration of runoff. Trees and shrubs along the swale can provide shade and mulch which decrease evaporation.
== On beaches ==
The term "swale" or "beach swale" is also used to describe long, narrow, usually shallow troughs between ridges or sandbars on a beach, that run parallel to the shoreline.
== See also ==
Contour trenching
Gutter
Keyline design
Rain garden
Stormwater
Water-sensitive urban design
== References ==
== External links ==
Fact Sheet: Dry and Wet Vegetated Swales from Federal Highway Administration
Wetlands of the Great Lakes: The Beach Swale & Dune and Swale Types from Michigan State University
Video showing swales used to rehabilitate desert terrain
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Landforms
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Swell (geology)
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A swell in geology is a domed area of considerable areal extent.According to Leser, it is also called a sill (geology), and is a gently arched landform of various orders of size in topographic, sub-glacial or sub-hydric geology. It may be as small as a rock formation in a river or may assume continental scale.
== References ==
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Landforms
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Syrt
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A syrt is a kind of an elevated landform in Russia and Central Asia.
The word means "highland", "ridge" or "backbone" in Turkic languages (sırt) and is present in Turkic toponymy in the mentioned areas: in Tien Shan, Pamirs, South Urals, such as Obshchiy Syrt by Urals, Uzun-Syrt ("Long back") plateau by Koktebel in Crimea.
It is a denudational upland or elevated flatland, a kind of dissected plateau. Syrts may be separated from each other by higher ridges. At the same time, syrts may serve as water divides between drainage basins for larger rivers.
The term should not to be confused with the Latin term syrtis and the derived term "syrt" for sandy shores or quicksand.
== See also ==
Summit accordance
== References ==
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Landforms
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Table (landform)
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A table or tableland is a butte, flank of a mountain, or mountain, that has a flat top.
This kind of landform has numerous names, including:
Butte
Mesa
Plateau – Highland area, usually of relatively flat terrain
Potrero
Tepui
Terrace
TuyaA homologous landform under the sea is called a tablemount or guyot.
== Description ==
The term "flat" is relative when speaking of tables, and often the naming or identification of a table (or table hill or mountain) is based on the appearance of the terrain feature from a distance or from below it. An example is Mesa Verde, Colorado, where the "flat top" of the mountain is both rolling terrain and cut by numerous deep canyons and arroyos, but whose rims appear quite flat from almost all directions, terminating in cliffs.
== See also ==
Tablelands (disambiguation)
== External links ==
Media related to Tables (landform) at Wikimedia Commons
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Landforms
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Terrace (geology)
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In geology, a terrace is a step-like landform. A terrace consists of a flat or gently sloping geomorphic surface, called a tread, that is typically bounded on one side by a steeper ascending slope, which is called a "riser" or "scarp". The tread and the steeper descending slope (riser or scarp) together constitute the terrace. Terraces can also consist of a tread bounded on all sides by a descending riser or scarp. A narrow terrace is often called a bench.The sediments underlying the tread and riser of a terrace are also commonly, but incorrectly, called terraces, leading to confusion.
Terraces are formed in various ways.
== Fluvial terraces ==
Fluvial terraces are remnants of the former floodplain of a stream or river. They are formed by the downcutting of a river or stream channel into and the abandonment and lateral erosion of its former floodplain. The downcutting, abandonment, and lateral erosion of a former floodplain can be the result of either changes in sea level, local or regional tectonic uplift; changes in local or regional climate; changes in the amount of sediment being carried by the river or stream; change in discharge of the river; or a complex mixture of these and other factors. The most common sources of the variations in rivers and streams that create fluvial terraces are vegetative, geomorphic, and hydrologic responses to climate. More recently, the direct modification of rivers and streams and their watersheds by cultural processes have resulted in the development of terraces along many rivers and streams.
== Kame terraces ==
Kame terraces are formed on the side of a glacial valley and are the deposits of meltwater streams flowing between the ice and the adjacent valley side.
== Marine terraces ==
A marine terrace represents the former shoreline of a sea or ocean. It can be formed by marine abrasion or erosion of materials comprising the shoreline (marine-cut terraces or wave-cut platforms); the accumulations of sediments in the shallow-water to slightly emerged coastal environments (marine-built terraces or raised beach); or the bioconstruction by coral reefs and accumulation of reef materials (reef flats) in intertropical regions.The formation of a marine terrace follows this general process: A wave cut platform must be carved into bedrock (high wave energy is needed for this process). Although this is the first step to the process for the formation of a marine terrace, not all wave cut platforms will become a marine terrace. After the wave cut platform is formed it must be removed from interaction with the high wave energy. This process happens by either change in sea level due to glacial-interglacial cycles or tectonically rising landmasses. When the wave cut has been raised above sea level it is preserved. The terraces are most commonly preserved in flights along the coastline.
== Lacustrine terraces ==
A lake (lacustrine) terrace represents the former shoreline of either a nonglacial, glacial, or proglacial lake. As with marine terraces, a lake terrace can be formed by either the abrasion or erosion of materials comprising the shoreline, the accumulations of sediments in the shallow-water to slightly emerged environments, or some combination of these. Given the smaller size of lakes relative to the size of typical marine water bodies, lake terraces are overall significantly narrower and less well developed than marine terraces. However, not all lake terraces are relict shorelines. In case of the lake terraces of ancient ice-walled lakes, some proglacial lakes, and alluvium-dammed (slackwater) lakes, they often represent the relict bottom of these lakes. Finally, glaciolacustrine kame terraces are either the relict deltas or bottoms of ancient ice marginal lakes.
== Structural terraces ==
In geomorphology, a structural terrace is a terrace created by the differential erosion of flat-lying or nearly flat-lying layered strata. The terrace results from preferential stripping by erosion of a layer of softer strata from an underlying layer of harder strata. The preferential removal of softer material exposes the flat surface of the underlying harder layer, creating the tread of a structural terrace. Structural terraces are commonly paired and not always associated with river valleys.
== Travertine terraces ==
A travertine terrace is formed when geothermally heated supersaturated alkaline waters emerge to the surface and form waterfalls of precipitated carbonates.
== See also ==
Parallel Roads of Glen Roy – Nature reserve in the Highlands of Scotland with ancient shoreline terraces
Machair – Fertile low-lying grassy plain
Piedmonttreppen
Raised beach – Emergent coastal landform
Raised shoreline – Ancient shoreline exposed above current water level
Terrace (earthworks) – Terrain formed by tiered platforms
Terrace Crossing - a geographical zone between the sedimentation (downstream) part and the erosion (upstream) part of a river
Wave-cut platform – Narrow flat area created by erosion
== References ==
== External links ==
Here is a good example of a river terrace: http://www.geographie.uni-erlangen.de/mrichter/gallery/photos/asia/images/river_terraces_near_kasbeki.jpg
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Landforms
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Thalweg
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In geography and fluvial geomorphology, a thalweg or talweg () is the line of lowest elevation within a valley or watercourse.Under international law, a thalweg is taken to be the middle of the primary navigable channel of a waterway that defines the boundary line between entities such as states. Thalwegs can acquire special significance because disputed river borders are often deemed to run along the river's thalweg.
== Etymology ==
The word thalweg is of 19th-century German origin. The German word Thalweg (modern spelling Talweg) is a compound noun that is built from the German elements Thal (since Duden's orthography reform of 1901 written Tal) meaning valley (cognate with dale in English), and Weg, meaning way. It literally means "valley way" and is used, with its modern spelling Talweg, in daily German to describe a path or road that follows the bottom of a valley, or in geography with the more technical meaning also adopted by English.
== Hydrology ==
In hydrological and fluvial landforms, the thalweg is a line drawn to join the lowest points along the entire length of a stream bed or valley in its downward slope, defining its deepest channel. The thalweg thus marks the natural direction (the profile) of a watercourse.
The term is also sometimes used to refer to a subterranean stream that percolates under the surface and in the same general direction as the surface stream.
== Real world application ==
Slowing stream-bed erosion by taking advantage of a thalweg helps stabilize running water sources. Placing boulders along the thalweg in a running water source helps to protect the channel's sedimentary erosion and deposit balance. In concurrence with the placement of boulders along a thalweg, the placement of boulders along an instream to form artificial sills also helps to slow the sedimentary erosion and deposit of running water sources, while keeping the esteem (fishing, local wildlife, and recreation) and natural resources of the running water source intact. The placement of boulders along a thalweg and the creation of instream sills help to aid the flow of water during late summer months when the flow rate drops, and help to slow sedimentary erosion and deposit in the spring and fall months when the flow rates are high. This process of utilizing a thalweg to slow stream-bed erosion was used in Meacham Creek in Umatilla, Oregon.
== Thalweg principle ==
The thalweg principle (also known as the thalweg doctrine or the rule of thalweg) is the legal principle that if the boundary between two political entities is stated to be a waterway, without further description (e.g., a median line, right bank, eastern shore, low tide line, etc.), the boundary follows the thalweg of that watercourse. In particular, the boundary follows the center of the principal navigable channel of the waterway (which is presumably the deepest part). If there are multiple navigable channels in a river, the one principally used for downstream travel (likely having the strongest current) is used. This definition has been used in specific descriptions as well. The Treaty of Versailles, for example, specifies that "In the case of boundaries which are defined by a [navigable] waterway" the boundary is to follow "the median line of the principal channel of navigation."The precise drawing of river boundaries has been important on countless occasions. Notable examples include the Shatt al-Arab between Iraq and Iran, the Danube in central Europe (Croatia–Serbia border dispute), the Kasikili/Sedudu Island dispute between Namibia and Botswana (settled by the International Court of Justice in 1999), and the 2004 dispute settlement under the UN Law of the Sea concerning the offshore boundary between Guyana and Suriname, in which the thalweg of the Courantyne River played a role in the ruling. In the 20th century dispute between the USSR and China (PRC) over Zhenbao Island, China held that the Thalweg principle supported their position. The doctrine is also applied to sub-national boundaries, such as those between American states.In rivers with occasional flooding and especially ice cover which breaks in the spring, the thalweg can change. This can mean that the border might move if it is defined as the thalweg. The Finland–Sweden border has been moved several times due to this.
== Mathematics ==
In the field of topology, the thalweg can be described as a parametrised curve. If the elevation of the valley floor at some position with coordinates (x, y) is represented by a surface z(x, y), then the negative gradient vector field -∇z(x, y) equips each position (x, y) with a vector pointing downhill in the direction of steepest slope (or by analogy, the direction a ball would roll if released from this position in the valley). Any parametrised curve that is everywhere directed along the gradient vector field eventually joins the thalweg (or using the same analogy, you can release a ball from any position in the valley, and it will eventually meet and then roll along the thalweg, assuming a smooth rolling surface so the ball doesn't get stuck, and also assuming sufficient rolling resistance or wind resistance that the ball doesn't roll down one side of the valley, up the other side and then oscillate back and forth). So, in this sense, the thalweg can be defined as the parametrised curve to which the gradient field converges.
== See also ==
Stream gradient – Surface slope along a watercourse
== References ==
== External links ==
USGS: Stream Modeling website
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Landforms
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Thule Land Bridge
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The Thule Land Bridge (also called the Thulean North Atlantic Bridge) was a land bridge, now submerged beneath the Atlantic Ocean, that connected the British Isles to central Greenland. The land bridge appeared during the Late Paleocene and disappeared during the early Eocene. The Thule Land Bridge is theorized to have connected northern Europe to North America by way of the British Isles and Greenland.
The Faroe Islands, the Iceland-Faroe Ridge, Iceland, and the shallow portion of the Denmark Strait may have been parts of the Thule Land Bridge.
== Relation to other land bridges ==
While it existed, the Thule Land Bridge would have connected Doggerland to Greenland.
It is also theorized that the completion of the land bridge from Europe to North America was completed with an unnamed crossing at the southern portion of the Davis Strait, connecting Greenland to Baffin Island.
== References ==
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Landforms
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Velma (mudflat)
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Velma (plural velme) is a Venetian dialect term derived from "melma" (mud). It is also used by Italian scientists to refer to lagunar mudflats (also called tidal flats), such as those found in the Lagoon of Venice. They are areas of shallow lagunar bottoms which are normally submerged, but emerge at low tides. They are generally without vegetation. Only associations of Zostera noltii (dwarf eelgrass) can be found. They originate from sediments carried by sea and stronger currents which are deposited on the lagoon bottom. They often surround the edges of the lagoon's barene (a venetian term for saltmarshes).The velme, together with the barene (saltmarshes) and the shallow bottoms, constitute one of the most characteristic but also most fragile environments of the ecosystem of the Lagoon of Venice. They are subject to variations in their extent depending on the amount of materials (silt, sand and other sediments) they lose or acquire. Sediment acquisition leads to the consolidation of the velma's sediment soil and sediment loss leads to erosion of this soil. If the balance between consolidation and erosion fails, the velme and saltmarshes risk disappearing.
== Erosion and loss of velma areas ==
The loss of velma areas in the Lagoon of Venice has been occurring for more than two centuries. From the early 19th century the combined saltmarsh area had decreased form 155 km2 to 40 km2. This has also involved a loss of velma areas because many of them surround the saltmarshes.
Velma areas are often under bathymetric (depth) pressure, which makes them less likely to emerge at low tides, leading to loss of stability and potential loss of their ecological function. This has been caused by infrastructural works carried out in the last two centuries. In the 19th century breakwaters were built at the lagoon inlets to stabilise their shape and orientation and to intensify the inflow of sea current in order to create conditions for deepening them and the channels which start from them. This was done to facilitate the transit of larger ships into the lagoon. In the 20th century, an even deeper and wider navigation canal was dug from the Malamocco inlet to the port of Marghera for large container ships and oil tankers to sail to new industrial areas. The depth of the channel form the Lido inlet was also increased to let large modern cruise ships through. These kinds of interventions have led to the displacement of sediments which are lost out of the lagoon and an increase in depth of the lagoon floor form and average of -0.75 m to one of -1.5 m since 1902.The average loss of sediments is 2.2 million m3 per year. Erosion in the Lido basin was 14 cm in 1930-1970 and 12 cm in 1970-2000; in the Malamocco basin it was 20 cm and 33 cm respectively; in the Chioggia basin it was 8 cm and 20 cm; in the mid lagoon 14 cm and 20 cm.The average deepening of lagoon floor has also made the wave action created by winds stronger, producing a further erosive effect. In addition to normal strength winds, Venice can also be hit by strong winds
caused the Bora from the northeast, especially in the winter, or the Scirocco from the southeast, which can occur from March to November. The latter, when combined a rising tide, can cause the acqua alta phenomenon (exceptionally high tides which cause flooding). Another erosive problem is caused by wave action created by passing motorboats.
== Shelter for benthic species ==
The velme are ecologically important because strong variations in salinity and oxygenation created by submersion and emersion turn them into an environment which is even more selective than that of the saltmarshes. As a result, they form Benthic zones. Their substratum gives shelter to Benthos (lagoon bottom species): polychaetes (bristle worms), Daphnia (water fleas), molluscs (particularly bivalves) and some small crustaceans, such as caridean shrimps, from the low tide. These, in turn, provide food for some species of water birds, both nesting and migratory.
== Food source for birds ==
Waders (called shorebirds in North America) are associated with the tidal variations in water level. They are found in mudflats which are exposed at low tide and or just about underwater in very shallow waters, where they search for their Benthos preys in the mud. Their thin, pointed beaks penetrate the mud to catch preys which do not have significant reactions. Their short legs allow them to walk where the water is only a few centimetres deep. Their legs and beaks are often brightly coloured, but their prey cannot see them and flee. During high tides, when their food is underwater, they rest at Roost sites. Some species feed throughout the tidal cycle shifting their feeding between mudflats and saltmarshes in synchrony with the tide rises and falls. The loss of mudflats and saltmarshes and disturbance at feeding and roosting sites poses a considerable threat to these populations. Their dependence on the presence of mudflats is a problem as these are one of the most difficult lagunar areas to restore and maintain. Many species are strongly migratory. They nest in northern Europe and Asia and winter on the Atlantic and Mediterranean coasts. Decreased food availability forces migratory species to prolong their flight periods, which results in a decrease in reproductive success and increase mortality.Common waders in the lagoon are the black-winged stilt (Himantopus himantopus), pied avocet (Recurvirostra avosetta), Eurasian curlew (Numenius arquata), black-tailed godwit (Limosa limosa), common redshank (Tringa totanus), spotted redshank (Tringa erythropus), common greenshank (Tringa nebularia) and Eurasian oystercatcher (Haematopus ostralegus). The common redshank's nesting colony in the lagoon the largest in the Mediterranean, with 2000 specimens.
== Seagrass of the velma ==
Zostera noltii (dwarf seagrass) and especially its subspecies Nanozostera noltii, which is more common in the Lagoon of Venice, are found in velma areas. Like other seagrasses, they are important for stabilising, re-suspending and consolidating sediments. They provide a defence against erosion and reduce wave energy. They also protect the benthic species that live in the velme. An area where it has been planted in a raised artificial velma habitat at Punta vecia Sud had been colonised by 47 benthic taxa. The biomass is seven times higher than that of the areas nearby. Zostera is, however, sensitive to being smothered by shifting sediments and has a low capacity to recover when buried. This may be due to its relatively short leaves and its lack of vertical rhizomes.In addition the mentioned roles, it plays an important part in the winter diet of the whooper and mute swan, the brent goose, wigeon and wildfowl.
== Protection of the velme ==
In the Lagoon of Venice some velma areas have been undergoing marked degradation due to the inconsistent nature of the bottom sediments or erosion. Consequently, there is degradation of the benthic species in the bottom sediments of the lagoon with pronounced bathymetric (depth) pressure. Projects to recover and regenerate these areas have been undertaken with the creation of new velma structures by creating confined areas and pouring sedimentary materials which include sandy and loamy components into them, using in part or totally materials from the dredging of the lagoon inlets. In areas under bathymetric pressure the bottom of the lagoon was increased in height to make it shallower. Small vivification canals were dug to direct the flow of water, improve sea water turnover and activate the processes of stabilisation of the bottom through an increase of primary production. Since these structures reach their highest physical and environmental value when they are colonised by Nanozostera noltii, a seagrass typical of the intertidal flats, these were planted in the intervention areas.In the twenty-five years up to 2016, 18 artificial velma habitats covering a total of 2 km2 were created. This, together with the creation 11 km2 of saltmarshes, involved the reuse of 20 million m3 of sediments from the dredging of channels and canals. The creation of more velma habitats was in progress and more were planned. There is also a wider programme of planting seagrasses which also involves the planting of Cymodocea nodosa (little Neptune grass). It is found mainly near the inlets or in places with medium to high hydrodynamics and where salinity is not variable. It likes sediments with a high sand content. As it is of tropical origin, it starts growing rapidly in late spring, assuming an emerald colour, and does not grow in the winter, assuming a brownish colour. It is planted by the inlets or in canals or channels not far from them at a depth on -1.5 m or in artificial velma habitats in conjunction with Nanozostera noltii.
== References ==
== External links ==
Adriatic Sea
Lagoon of Venice
Mudflats
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Landforms
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Washland
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Washland or washes are areas of land adjacent to rivers which are deliberately flooded at times when the rivers are high, to avoid flooding in residential or important agricultural areas. They often provide for overwintering wildfowl, and several include important nature reserves.Examples of washlands include:
The Ouse Washes of Cambridgeshire and Norfolk
The Nene Washes of Cambridgeshire
== References ==
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Landforms
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Waulsortian mudmound
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A Waulsortian mudmound is a calcareous geographical feature found in Early Carboniferous strata of Central Europe. It is a type of fossil-rich bioconstruction, formed by microbial activity in deep tropical waters during the mid-Dinantian (late Tournaisian to early Viséan geological age). Mud mounds are a type of high-relief biologically-mediated seafloor deposit, similar to a reef. Unlike a true reef, a mud mound is composed almost entirely of uncemented mud-sized matrix grains, and the isolated fossils do not form a significant skeletal framework.
Waulsortian mudmounds in particular are unbedded, micritic limestone, heavily jointed with calcite veining. There is some galena and sphalerite mineralisation in the joints. The fossils are mainly crinoid ossicles and fenestellid bryozoans, together with gastropods and brachiopods.
The term Waulsortian was first used in 1863 to describe an area of limestone near Waulsort in Namur, Belgium. Similar mudstone was recognised in the Clitheroe area of Lancashire England by Arthur Vaughan in 1916.
== Formation ==
On a firm bed of limestone, under the deep waters of the tropical sea, crinoids fixed themselves to the rock. The oceans gentle currents eroded the base rock creating a lime-rich mud which was propelled by the current. Where the water was too rapid, the crinoids were displaced, but where it was slower they formed a barrier which arrested the mud forming a micritic deposit. Further crinoids attached themselves, and the deposit thickened to an eventual depth of 200m. In the mudmound one finds fossils of the crinoids bone structure and the angle of deposit shows the direction and speed of mudflow.
== Clitheroe reef belt ==
There has been much debate on how the low micritic limestone hills in the Craven Basin were formed, one theory led to them being called reef knolls, knoll reefs, or bioherms but work in 1972 by Miller & Grayson identified them as mud mounds with the same fossil content as those near Waulsort. They include accessible geological sites at Clitheroe Castle, Salthill and Bellman quarries, Crow Hill and Worsaw, Gerna and Sykes.
== References ==
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Landforms
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Windwatt
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A Windwatt is a mudflat exposed as a result of wind action on water. They occur especially in the Western Pomerania Lagoon Area National Park on Germany's Baltic Sea coast. The term is German.Unlike the Wadden Sea along Europe's North Sea coast, the shallow water zones of the Western Pomerania Lagoon Area National Park are largely unaffected by oceanic tides. When there are strong winds in a certain direction, however, water is driven out of the lagoons (the so-called bodden) into the Baltic Sea, so that several particularly shallow areas of mud become exposed and dry out. The water flows back when the wind turns again.
These Windwatten are a major source of food for migrating birds in the autumn. For the Crane, which cross Western Pomeranian bodden country during migration, the Windwatten are one of the most important resting areas in Western Europe.
== References ==
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Landforms
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Witness Hill
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A witness hill is a type of landform created from the erosion of the earth. It is a testimony of the evolution and retreat of a platform or cuesta relief, that is, it is a rest of the platform in a relief where there are layers of hard and soft rocks arranged horizontally in which erosion has sculpted landscapes that are also horizontal. As the erosion produced by the rivers increases in the soft layers, hills are formed, and if the plateau is attacked by erosion from all sides, the witness hills with flat summits appear. They are therefore, the "witnesses" of the platform that existed in that place millions of years ago.Some examples of this type of geological formation are: Pilot Mountain, North Carolina, Dori Plateau, Burkina Faso, La Teta Hill, La Guajira Peninsula and the Hills of Guayana, Venezuela. These hills are quite common in the sedimentary basins of the Meseta Central of the Iberian Peninsula, in the Ebro Depression and in the tabular reliefs.
== References ==
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Landforms
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Category:Landforms by mountain range
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Category:Landforms by place
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Category:Ecoregions by landform
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Category:Lists of landforms
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Category:Bodies of water
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Compare to Category:Landforms and Category:Wetlands
Bodies of water may exist within land areas or within other bodies of water and may be natural, human-made or a combination.
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Category:Aeolian landforms
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Category:Artificial landforms
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Artificially created landforms, using various types of engineering vehicles.
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Landforms
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Category:Basins
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This is the category for geologic basins and geographical basins, including geologic oceanic basins, sedimentary basins, geologic depression basins, drainage basins (aka watersheds), and groundwater basins. Some of these are usually thought of in their two-dimensional representation as on a map, however they are all three-dimensional bodies. They are all landforms, even if some of them are under water or under other overburden.
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Category:Coastal and oceanic landforms
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Coastal landforms and Physical oceanography topographic landforms.
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Category:Coastal lagoons
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Category:Continents
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Category:Geologic domes
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Category:Glacial landforms
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Landforms created by glaciers
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Landforms
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Category:Glens
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Articles about glens, a type of valley, typically one that is long and bounded by gently sloped concave sides.
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Landforms
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Category:Highlands
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Articles relating to highlands, mountainous regions or elevated mountainous plateaus. Generally speaking, upland (or uplands) refers to ranges of hills, typically up to 500–600 m (1,600–2,000 ft). Highland (or highlands) is usually reserved for ranges of low mountains.
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Landforms
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Category:Islands
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"Islands by country" refers to sovereignty, which may be different from physical location.
"Islands by continent" also refers to sovereignty.
"Islands by body of water" refers to physical location, specifically:
"Islands in lakes"
"Islands by ocean or sea"
"River islands".
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Landforms
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Category:Karst
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Landforms
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Category:Lacustrine landforms
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Category:Mountain ranges
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Category:Mountains
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Related categories:
Category:Climbing
Category:Hills
Category:Mountain ranges
Category:Mountaineering
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Landforms
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Category:Mud volcanoes
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Landforms
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Category:Patterned grounds
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Patterned grounds may have different origins, amongst others:
Cryoturbation (ice wedges, palsa and pingo);
Desiccation;
Water expulsion by squeezing;
Lava recrystallisation.
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Category:Periglacial landforms
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Landforms
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Category:Volcanic landforms
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Volcanic landforms
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Landforms
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Category:Wikipedia categories named after landforms
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Islands
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Island
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An island or isle is a piece of subcontinental land completely surrounded by water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An island in a river or a lake island may be called an eyot or ait, and a small island off the coast may be called a holm. Sedimentary islands in the Ganges Delta are called chars. A grouping of geographically or geologically related islands, such as the Philippines, is referred to as an archipelago.
There are two main types of islands in the sea: continental islands and oceanic islands. There are also artificial islands (man-made islands).
There are about 900,000 official islands in the world. This number consists of all the officially-reported islands of each country. The total number of islands in the world is unknown. There may be hundreds of thousands of tiny islands that are unknown and uncounted. The number of sea islands in the world is estimated to be more than 200,000. The total area of the world's sea islands is approx. 9,963,000 sq km, which is similar to the area of Canada and accounts for roughly 1/15 (or 6.7%) of the total land area of Earth.
== Etymology ==
The word island derives from Middle English iland, from Old English igland (from ig or ieg, similarly meaning 'island' when used independently, and -land carrying its contemporary meaning; cf. Dutch eiland ("island"), German Eiland ("small island")). However, the spelling of the word was modified in the 15th century because of a false etymology caused by an incorrect association with the etymologically unrelated Old French loanword isle, which itself comes from the Latin word insula. Old English ieg is actually a cognate of Swedish ö and German Aue, and related to Latin aqua (water).
== Relationships with continents ==
=== Differentiation from continents ===
There is no standard of size that distinguishes islands from continents, or from islets.There is a widely accepted difference between islands and continents in terms of geology. Continents are often considered to be the largest landmass of a particular continental plate; this holds true for Australia, which sits on its own continental lithosphere and tectonic plate (the Australian Plate).By contrast, islands are usually seen as being extensions of the oceanic crust (e.g. volcanic islands), or as belonging to a continental plate containing a larger landmass (continental islands); the latter is the case of Greenland, which sits on the North American Plate.
=== Continental islands ===
Continental islands are bodies of land that lie on the continental shelf of a continent. Examples are Borneo, Java, Sumatra, Sakhalin, Taiwan and Hainan off Asia; New Guinea, Tasmania, and Kangaroo Island off Australia; Great Britain, Ireland, and Sicily off Europe; Greenland, Newfoundland, Long Island, and Sable Island off North America; and Barbados, the Falkland Islands, and Trinidad off South America.
==== Microcontinental islands ====
A special type of continental island is the microcontinental island, which is created when a continent is horizontally displaced or rifted. Examples are Madagascar and Socotra off Africa, New Caledonia, New Zealand, and some of the Seychelles.
==== Subcontinental islands ====
A lake such as Wollaston Lake drains in two different directions, thus creating an island. If this island has a seashore as well as being encircled by two river systems, it becomes what might be called a subcontinental island. The one formed by Wollaston Lake is very large, about 2,000,000 km2 (770,000 sq mi).
==== Bars ====
Another subtype is an island or bar formed by deposition of tiny rocks where water current loses some of its carrying capacity. This includes:
barrier islands, which are accumulations of sand deposited by sea currents on the continental shelves
fluvial or alluvial islands formed in river deltas or midstream within large rivers. While some are transitory and may disappear if the volume or speed of the current changes, others are stable and long-lived.
=== Oceanic islands ===
==== Tectonic versus volcanic ====
Oceanic islands are typically considered to be islands that do not sit on continental shelves. Other definitions limit the term to only refer to islands with no past geological connections to a continental landmass. The vast majority are volcanic in origin, such as Saint Helena in the South Atlantic Ocean. The few oceanic islands that are not volcanic are tectonic in origin and arise where plate movements have lifted up the ocean floor above the surface. Examples are the Saint Peter and Saint Paul Archipelago in the North Atlantic Ocean and Macquarie Island in the South Pacific Ocean.
==== Volcanic islands ====
===== Arcs =====
One type of volcanic oceanic island is found in a volcanic island arc. These islands arise from volcanoes where the subduction of one plate under another is occurring. Examples are the Aleutian Islands, the Mariana Islands, and most of Tonga in the Pacific Ocean. The only examples in the Atlantic Ocean are some of the Lesser Antilles and the South Sandwich Islands.
===== Oceanic rifts =====
Another type of volcanic oceanic island occurs where an oceanic rift reaches the surface. There are two examples: Iceland, which is the world's second-largest volcanic island, and Jan Mayen. Both islands are in the Atlantic Ocean.
===== Hotspots =====
A third type of volcanic oceanic island is formed over volcanic hotspots. A hotspot is more or less stationary relative to the moving tectonic plate above it, so a chain of islands results as the plate drifts. Over long periods of time, this type of island is eventually "drowned" by isostatic adjustment and eroded, becoming a seamount. Plate movement across a hot-spot produces a line of islands oriented in the direction of the plate movement. An example is the Hawaiian Islands, from Hawaii to Kure, which continue beneath the sea surface in a more northerly direction as the Emperor Seamounts. Another chain with similar orientation is the Tuamotu Archipelago; its older, northerly trend is the Line Islands. The southernmost chain is the Austral Islands, with its northerly trending part the atolls in the nation of Tuvalu. Tristan da Cunha is an example of a hotspot volcano in the Atlantic Ocean. Another hotspot in the Atlantic is the island of Surtsey, which was formed in 1963.
===== Atolls =====
An atoll is an island formed from a coral reef that has grown on an eroded and submerged volcanic island. The reef rises to the surface of the water and forms a new island. Atolls are typically ring-shaped with a central lagoon. Examples are the Line Islands in the Pacific Ocean and Maldives in the Indian Ocean.
== Tropical islands ==
Approximately 45,000 tropical islands with an area of at least 5 hectares (12 acres) exist. Examples formed from coral reefs include Maldives, Tonga, Samoa, Nauru, and Polynesia. Granite islands include Seychelles and Tioman.
The socio-economic diversity of tropical islands ranges from the Stone Age societies in the interior of North Sentinel, Madagascar, Borneo, and Papua New Guinea to the high-tech lifestyles of the city-islands of Singapore and Hong Kong. International tourism is a significant factor in the economy of many tropical islands including Seychelles, Sri Lanka, Mauritius, Réunion, Hawaii, Puerto Rico and the Maldives.
== De-islanding ==
The process of de-islandisation is often concerning bridging, but there are other forms of linkages such as causeways: fixed transport links across narrow necks of water, some of which are only operative at low tides (e.g. that connecting Cornwall's St Michael's Mount to the peninsular mainland), while others (such as the Canso Causeway connecting Cape Breton to the Nova Scotia mainland) are usable all year round (aside from interruptions during storm surge periods).Some places may retain "island" in their names for historical reasons after being connected to a larger landmass by a land bridge or landfill, such as Coney Island and Coronado Island, though these are, strictly speaking, tied islands. Conversely, when a piece of land is separated from the mainland by a man-made canal, for example the Peloponnese by the Corinth Canal, more or less the entirety of Fennoscandia by the White Sea Canal, or Marble Hill in northern Manhattan during the time between the building of the United States Ship Canal and the filling in of the Harlem River which surrounded the area, it is generally not considered an island.
Another type of connection is fostered by harbor walls/breakwaters that incorporate offshore islets into their structures, such as those in Sai harbor in northern Honshu, Japan, and the connection to the mainland which transformed Ilhéu do Diego from an islet. De-islanded through its fixed link to the mainland, the former islet's name, Ilhéu do Diego, became functionally redundant (and thereby archaic) and the location took the fort as its namesake. Some former island sites have retained designations as islands after the draining/subsidence of surrounding waters and their fixed linkage to land (England's Isle of Ely and Vancouver's Granville Island being respective cases in point). Their names are thereby archaic in that they reflect the islands' pasts rather than their present structures or transport logistics. Other examples include Singapore and its causeway, and the various Dutch delta islands, such as IJsselmonde.
== Artificial islands ==
Almost all of Earth's islands are natural and have been formed by tectonic forces or volcanic eruptions. However, artificial (man-made) islands also exist, such as the island in Osaka Bay off the Japanese island of Honshu, on which Kansai International Airport is located. Artificial islands can be built using natural materials (e.g., earth, rock, or sand) or artificial ones (e.g., concrete slabs or recycled waste).Sometimes natural islands are artificially enlarged, such as Vasilyevsky Island in the Russian city of St. Petersburg, which had its western shore extended westward by some 0.5 km in the construction of the Passenger Port of St. Petersburg.
Artificial islands are sometimes built on pre-existing "low-tide elevation," a naturally formed area of land which is surrounded by and above water at low tide but submerged at high tide. Legally these are not islands and have no territorial sea of their own.
== Island superlatives ==
Largest island: Greenland
Largest island in a lake: Manitoulin Island, Ontario, CanadaLargest lake island within a lake island: Treasure Island, in Lake Mindemoya on Manitoulin Island
Largest island in a river: Bananal Island, Tocantins, Brazil
Largest island in fresh water: Marajó, Pará, Brazil
Largest sand island: Fraser Island, Queensland, Australia
Largest artificial island: Flevopolder, the Netherlands (created 1969)
Largest uninhabited island: Devon Island, Nunavut, Canada
Most populous island: Java, Indonesia
Lowest island: Franchetti Island, Lake Afrera, Ethiopia
Island shared by largest number of countries: Borneo (Brunei, Indonesia, Malaysia)
Island with the highest point: New Guinea (Puncak Jaya, 4,884 m, 16,024 ft), Indonesia
Northernmost island: Kaffeklubben Island, Greenland
Southernmost island (not fully surrounded by permanent ice): Ross Island, Antarctica
Island with the most populated city: Honshu (Tokyo), Japan
Most remote island (from nearest land): Bouvet Island
Island with earliest known settlement: Sumatra (Lida Ajer cave), Indonesia
== See also ==
== References ==
== External links ==
Definition of island from United Nations Convention on the Law of the Sea
Listing of islands Archived February 14, 2008, at the Wayback Machine from United Nations Island Directory.
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Islands
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Lists of islands
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This is a list of the lists of islands in the world grouped by country, by continent, by body of water, and by other classifications. For rank-order lists, see the other lists of islands below.
== Lists of islands by country ==
=== Africa ===
=== Antarctica ===
=== Asia ===
=== Europe ===
=== North America ===
=== Oceania ===
=== South America ===
== Lists of islands by continent ==
== Lists of islands by body of water ==
By ocean:
By other bodies of water:
== List of ancient islands ==
== Other lists of islands ==
== External links ==
Island Superlatives
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Islands
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Portal:Islands
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Islands
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Aquapelago
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An aquapelago is an assemblage of marine and terrestrial elements in which the aquatic spaces are key to community livelihoods and to communities’ senses of identity and belonging. Aquapelago refers to the socially constructed spaces of island, coastal, lacustrine or riverine locations, where humans have developed particularly concentrated engagements with the marine environment for their livelihoods (such as fishing or gathering aquatic plants) or leisure (such as surfing or diving). A neologism, aquapelago denotes the manner in which environmental psychology has been key to various maritime communities and causes in recent years. For example, the famous Mabo decision on indigenous Australian native title in 1992, successfully argued that areas of the seabed, and the aquatic resources above them, were part of traditional Torres Strait Islander community territories and related senses of communal homelands.
== Concept and etymology ==
The term aquapelago was introduced in 2012 in Shima online journal of research into island and maritime cultures. The term subsequently gained momentum in geography, anthropology, and cultural studies, since it addresses a conceptual and lexical gap in topical discourse on the human relationship to nature. More recently, the concept has extended in reach to creative fields such as theatre, science fiction, and music.In its initial coinage, etymologically, the term replaces the initial two syllables of the well-known term archipelago with aqua in order to reassert the role of marine elements in aggregations of islands that has been largely lost from contemporary usage of archipelago. The concept has been further elaborated, linking it to livelihood activities and to the Japanese concept of shima (referring to islands and related distinct cultural landscapes). This concept is striking in that it conceives of combined terrestrial and aquatic spaces as, effectively, neighborhoods.
The concept of aquapelago has been envisaged as a reflection on the Anthropocene and as:
Subsequent developments of the concept have analysed its applicability to topics such as ocean spaces and national rights of access to these, cultural practices in Melanesian coastal societies and career making in island communities. The original analyses of the aquapelago have been further expanded by addressing metropolitan locales and providing a characterisation of Manhattan as an aquapelagic city that was subsequently critiqued and modified. While there have been critics of the concept, some who regard the term as unnecessary in that archipelagic analyses can be extended to address aquatic elements, writers from various disciplines have engaged with the concept in a positive manner, such as an exploration of the concept with regard to water ecology themed performance works in the journal Women’s Studies Quarterly and a discussion of a geopolitical aesthetic of the subterranean in the journal Geopolitics. Further, the lens of the aquapelago can act as a bridge between the fields of island studies and studies examining seasteading.
== Associated concepts ==
One significant development of the concept of the aquapelago has concerned the notion of there being an “aquapelagic imaginary).” This concept has been subsequently elaborated in a theme issue of the journal Shima on mermaids, mer-cultures and the aquapelagic imaginary to refer to the manner in which communities’ “engagements with their aquapelagic locales” in folk-/media-loric contexts can be understood to reflect upon and transcend “perceptions of the limits of human presence in and experience of aquatic spaces.” In an article analysing the creation of a modern mythic entity, the Ningen, a creature rumoured to inhabit the southern Pacific Ocean, there is a discussion about the aquapelagic imaginary as a “subset" of the "social imaginary”, which can be regarded as a historically determined “enabling but not fully explicable symbolic matrix within which a people imagine and act as world-making collective agents”.
== References ==
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Islands
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Boyuk Zira
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Boyuk Zira (Böyük Zirə), also known as Nargin, is an island in the Caspian Sea. It is one of the islands of Baku Archipelago located in the Baku bay near Baku city. Nargin Island is part of the Baku Archipelago, which consists of the following islands: Boyuk Zira, Dash Zira, Qum Island, Zenbil, Sangi-Mugan, Chikil, Qara Su, Khara Zira, Gil, Ignat Dash and a few smaller ones.
Boyuk Zira is the biggest island that separates the Bay of Baku from the sea south of the Absheron Peninsula. It has a length of 3.1 km, and a width of 900 m.
The northwestern side of the island is vertical and steep. There is little vegetation.
Caspian seals, sturgeon, and numerous types of birds, such as teal ducks, herring gulls, and grebes are some of the species that can be found on and around Boyuk Zira Island.
== Toponym ==
A modern name of the island is “Boyuk Zira”, which was also its initial name, and it is originated from the merging of two words – “boyuk” means “big” in Azerbaijani and “jazira” means “island” in Arabic.
Most of the names of islands in the Baku archipelago, including Boyuk Zira, were changed by the Russians and partially by Cossacks, who appeared in the Caspian Sea region in the 17th century. Boyuk Zira was also called Nargin, which is related to the name given by Peter the Great. The shape of this island reminded the Russian emperor of the island Nargen (now Naissaar) near Tallinn in the Gulf of Finland. German “Nargen” and Estonian “Nartingen” mean a “narrow strait”. In 1990, Nargin Island reverted to its indigenous name.
== Strategic significance ==
Boyuk Zira Island, located in the Caspian Sea, 5 km directly offshore from Baku port, is strategically significant for Azerbaijan and is under the authority of the Ministry of Defence of the Republic of Azerbaijan. The island is stony. In January, 2008 SOCAR finished construction of a 17 km long, 12–14 meters deep water line extending from Lökbatan township to Boyuk Zira Island.
== History ==
=== Beacon ===
A beacon on the island began to function on December 11, 1884. The beacon was constructed on the southern part of the island and provided ships with an opportunity to enter Baku Bay at night. The beacon is a stone residential building with three-metered tower on a roof, along with a lamp. A kerosene-wick burner, and then a gas lamp with a light-optic apparatus of the 4th degree, which was specially produced in Sweden, illuminates the way for ships.
In 1941, because of the beginning of the Great Patriotic War, the beacon building was blown up by order of the Soviet Military Command. Anti-aircraft guns were established on the island to defend Baku from German air raids, because the beacon building was a potential landmark for German aviators. The beacon was restored in 1958 and still functions. An 18m stone tower equipped with a complex optical-navigational system was built on the elevated middle part of the island. Servicing of the way is carried out by a watching method and personnel are changed every two weeks. The beacon's light can be seen 20–30 km from Baku. The beacon's power is provided by solar batteries, which give a charge of up to 7 days, and also by a diesel generator.
=== World War I ===
Nargin Island was the scene of tragic events in the history of Azerbaijan and Turkey during World War I. About ten thousand soldiers, as well as civilians, who were captured in 1914-1915 in Turkey during the occupation of Eastern Anatolia by the Russian army, were held in captivity on the island. The captives died of starvation, snake bites, and murder and torture by prison guards. Few prisoners managed to escaped island. According to Hasan Cüneyt Zapsu, a deputy and counselor of the Cabinet of Ministers of Turkey, his grandfather Abdurrahim Rahmi Zapsu was imprisoned on Nargin Island and escaped with the help of a nurse. Vecihi Hürkuş – a Turkish veteran pilot and aviation pioneer– also escaped from the island with the assistance of local residents, and a film dedicated to him is intended to be shot in Turkey.A documentary exposing the tragedy Turkish soldiers endured in Nargin island in the early 20th century was shot by order of the Ministry of Culture and Tourism of Turkey. Archive documents and scenes of those years, and also memories of 11 Turkish soldiers, who were in camps in Nargin Island and returned to the motherland alive, were used in the film called Hellish Nargin Island. In recent years, the erection of a monument on Nargin Island to the perished Turkish soldiers has been frequently proposed by Turhan Çömez, a former deputy of the Grand National Assembly of Turkey, and others.
=== Victims of repressions ===
Nargin Island was called the Azerbaijani gulag during the Stalin-era repression. It was the place of mass shootings and burials of Stalin-Beria terror victims, who were taken there in barges. Ten thousand people condemned by judicial communist “trios” were shot on the island, far from witnesses. Sometimes, barges full of people were sunk in order to save ammunition. According to scuba divers, there are still remains of people, tortured by the Soviet regime, tied with chains under water.
== Development plans ==
In 2009 a plan was mooted for turning Boyuk Zira Island into a carbon-neutral eco-resort and recreation centre with a profile based on Azerbaijan's seven best-known peaks. The cost of the project, known as “The dream island”, by Danish architects Bjarke Ingels Group (BIG), would have been around two billion US dollars. But as of 2015 there is no sign of the project advancing.
== Panoramic view ==
== Places of interest ==
The Boyuk Zira Lighthouse in the island was begun to function since 1884. It illuminated road for ships entering Bay of Baku. Until 1907, Maiden Tower executed these functions. But later, Nargin Island detaching Baku Bay from the sea, became the main guide for sailors. A kerosene-wick burner, and then a gas lantern with a light-optic apparatus of the 4th degree illuminated a road for ships. The Nargin lighthouse illuminated by acetylene in 1912, became the first lighthouse in the Russian Empire illuminated by such a way.
== References ==
== External links ==
Nargin photos
Zira Island masterplan project Archived 2017-05-15 at the Wayback Machine
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Islands
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Cikobia-i-Ra
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Cikobia-i-Ra, also Thikombia Island, Tchecombia and Tikobia, is the northernmost island in Fiji and has a primarily limestone geology. As the island is affected by climate change, women there have established the Cikobia Island Development Committee, which supports businesses that donate some profit to sustainability initiatives. The island has some of the earliest evidence for Lapita culture in the Pacific, as well as significant archaeological sites.
== Geography ==
Located to the north of Vanua Levu in Macuata Province in Fiji, Cikobia-i-Ra is 300 km to the northeast of Suva. The island is 10 km long and 2km wide; it is 60 km from the northernmost point of Vanua Levu. It is primarily made from uplifted limestone formations.Settlements on Cikobia-i-Ra include Nalele, Nautovatu and Vatulele.
== Climate crisis ==
Cikobia-i-Ra is the northernmost and the most remote of the islands in the Northern Division. The island has been affected by the climate crisis, including an increase in the number of natural disasters. In response, women from the island established the Cikobia Island Development Committee, which enables women to start businesses based on natural resources available to them. This then enables the women to return 10% of their earnings to sustainability projects on the island, so that "10 per cent of their earnings had been channelled towards their environment sustainability project."
== History ==
The island was first settled around 850 BC by people who were part of the Eastern Lapita cultural complex. According to oral tradition, Cikobia-i-Ra was settled by Manaoneata and his son Iri-ni-buno, who came from Laucala in Cakaudrove. One of Manaoneata's sons settled later on Naqelelevu. Other accounts, recorded by Bruce Biggs, state that a chief called Sau Mata-i-walu spent time in Cikobia-i-Ra before discovering Naqelelevu.Cikobia-i-Ra's language is most closely related to Naqelelevu's and exchanges between the two islands and the island of Futuna have been reconstructed through linguistic analysis.
=== Korotuku complex ===
At Korotuku a defensive fort was built, which contained ninety different structures, as well as burials. In 1997 a team of archaeologists from Fiji and France investigated the archaeological remains on the island. They identified twenty-five funerary sites on the island, most of which related to the historic period (c.1850), and whose history is attested in the island's oral culture. The team excavated ten internments, which included two children and eight adults, five of whom could be identified as males, two of which females. A number of grave goods were found, including glass trade beads, a qato – which is an armband made of Trochus shell, a boar's tusk, a shark's tooth and a coral object which was tentatively identified as part of a tabua – a ceremonial object which accompanied a person into the afterlife. It is likely that the bodies were wrapped in tapa prior to burial. A later study used stable isotope analysis to examine the diets of those buried there, concluding that they ate a diet based primarily on vegetal food, with some shellfish consumption, which has been interpreted as dietary selection which may indicate those buried were part of an island elite.As part of the archaeological work instigated in 1997, Fijian colleagues undertook oral history work with the island's community to better understand the site. In response, islanders began to rebuild one of the fortifications, known as Rukunikoro. Years after work ended, families still tended the project, explaining that they preferred to keep tourists away, that it was for themselves, not for others.Glass beads have been excavated from graves on the island, which originated in Europe in the nineteenth century and may have been brought to the island by American whalers or European sailors, during the period of colonisation.
=== Intangible heritage ===
The Archive of Māori and Pacific Sound at the University of Auckland holds recordings made on the island by Bruce Biggs in 1974.
== Notable people ==
Penina Namata, advisor to Cikobia Island Development Committee.
== References ==
== External links ==
Trip to Cikobia Island (documentary)
Defensive wall at a fortified site on Cikobia-i-Ra, Fiji (image)
Seasea, a dance, being performed in Fiji (image)
Na Ciri Kali: The Oral Tradition of Cikobia-i-ra, Northernmost Island of the Fijian Group (book)
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Islands
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First island chain
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The first island chain refers to the first chain of major Pacific archipelagos out from the East Asian continental mainland coast. It is principally composed of the Kuril Islands, the Japanese archipelago, the Ryukyu Islands, Taiwan (Formosa), the northern Philippines, and Borneo, hence extending all the way from the Kamchatka Peninsula in the northeast to the Malay Peninsula in the southwest. The first island chain forms one of three island chain doctrines within the island chain strategy in the U.S. foreign policy.
Much of the first island chain is roughly situated in waters claimed by China. These include the South China Sea, within the nine-dash line, as well as the East China Sea west of the Okinawa Trough.
== Strategic value ==
=== China ===
According to a 2018 United States Department of Defense report to Congress, the People's Liberation Army's Anti-Access/Area Denial military capabilities aimed at the first island chain are its most robust. The report also stated that the People's Liberation Army Navy's ability to perform missions beyond the first island chain is "modest but growing as it gains experience operating in distant waters and acquires larger and more advanced platforms."
=== Japan ===
Around 2009 Japanese military strategist Toshi Yoshihara and Naval War College professor James R. Holmes suggested the American military could exploit the geography of the first island chain to counter the People's Liberation Army Navy build-up. The Cabinet of Japan has also passed defense white papers emphasizing the threat posed by the People's Liberation Army Navy in the first island chain.In the later years of the 2010s, Japan started deploying military assets to Yonaguni and its other islands to counter China's presence along that area of the first island chain.Japan's strategic position in the first island chain began with US-Japan joint efforts to counter Soviet expansion. The Japan Self-Defense Forces currently plays the role of protecting US military bases and preserving military strength in East Asia. As for Japan's Territorial Protection Self-Defense Forces, which mainly rely on islands in southern Japan adjacent to the Yellow Sea and the East China Sea, Japan has military advantages in anti-submarine, air defense and sea mine technologies.
=== Philippines ===
In 2021, Lloyd Austin, on behalf of the United States, thanked his counterpart in the Philippines Delfin Lorenzana for retaining the 70-year-old visiting forces agreement between the two nations. In 2023 four new bases were announced in the Philippines.
=== Taiwan ===
In the First Island Chain, Taiwan is considered of critical strategic importance. It is located at the midpoint of the first chain and occupies a strategic position.
=== United States ===
U.S. General Douglas MacArthur pointed out that before World War II, the US protected its western shores with a line of defense from Hawaii, Guam, to the Philippines. However, this line of defense was attacked by Japan with the Pearl Harbor bombing of 1941, thereby drawing the U.S. into the war. The US subsequently launched the air Raid on Taipei (called Taihoku under Japan's empire) and launched the atomic bombings of Hiroshima and Nagasaki. The WW2 victory allowed the US to expand its line of defense further west to the coast of Asia, and thus the US controlled the first island chain. Between the end of WW2 and the Korean War, MacArthur praised Taiwan, located at the midpoint of the first island chain, as an 'unsinkable aircraft carrier'.In April 2014, the United States Naval Institute (USNI) assessed that the first island chain is the most effective point to counter any Chinese invasion. The US could not only cut off the People's Liberation Army Navy from entering the western Pacific, but also predict where they may move before trying to break through in the first place. The US and first island chain countries are able to coordinate because of the US military's freedom of navigation in the first chain block. A June 2019 article published by the United States Naval Institute (USNI) called for the navy to establish and maintain a blockade around the first island chain if the US was go to war with China.Andrew Krepinevich argued that an "archipelagic defense" of the countries that make up the first island chain would make up a big part of the implementation of the national defense strategy of 2018. A 2019 report by the Center for Strategic and Budgetary Assessments "proposes a U.S. military strategy of Maritime Pressure and a supporting joint operational concept, “Inside-Out” Defense, to stabilize the military balance in the Western Pacific and deny China the prospect of a successful fait accompli." The first island chain plays a central role in the report. In 2020, the United States Marine Corps started shifting its tactics in conjunction with the United States Navy to be deployed along or near the first island chain. In 2021, the United States Marine Corps announced a goal of three additional Pacific-based regiments.
== See also ==
Island chain strategy
United States foreign policy toward the People's Republic of China
AirSea Battle
Bamboo Curtain
Power projection
== References ==
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Islands
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Island ecology
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Island ecology is the study of island organisms and their interactions with each other and the environment. Islands account for nearly 1/6 of earth’s total land area, yet the ecology of island ecosystems is vastly different from that of mainland communities. Their isolation and high availability of empty niches lead to increased speciation. As a result, island ecosystems comprise 30% of the world’s biodiversity hotspots, 50% of marine tropical diversity, and some of the most unusual and rare species. Many species still remain unknown.
The diversity of species on islands is highly impacted by human activities such as deforestation and introduction of the exotic species. In response, ecologists and managers are directing attention towards conservation and restoration of island species. Because they are simple systems, islands provide an opportunity to study processes of extinction that can be extrapolated to larger ecosystems.
== Ecological processes on islands ==
Islands are attractive sites for ecological research because they provide clear examples of evolution in action. They show interesting patterns of colonization, adaptation, and speciation.
=== Colonization and establishment ===
Islands are surrounded by water, and may or may not exist as part of a continental land mass. Oceanic islands arise due to volcanic activity or reef growth, and usually subside over time due to erosion and changing sea levels. When islands emerge, they undergo the process of ecological succession as species colonize the island (see theory of island biogeography). New species cannot immigrate via land, and instead must arrive via air, water, or wind. As a result, organisms with high dispersal capabilities, such as plants and birds, are much more common on islands than are poorly dispersing taxa like mammals. However, some mammals are present on islands, presumably from swimming or riding on natural “rafts” that are washed away from the mainland.
Of the species that arrive, only some will be able to survive and establish populations. As a result, islands have fewer species than mainland habitats. Island populations are small and exhibit low genetic variability (see founder effect), but are isolated from the predators and competitors that they initially evolved with. This can lead to a process called ecological release, where a species is released from its ancestral community interactions and then colonizes new niches.
=== Adaptation ===
In response to these changing ecological pressures, island species can become much more docile than their mainland counterparts, and may grow larger (see island gigantism) or smaller (see island dwarfism). Some of these unique adaptations are reflected in charismatic island species such as the Malagasy hippopotamus, Komodo dragon, or pygmy mammoths. Although, the giant tortoises of the Galápagos Islands and the Seychelles (the Galápagos tortoise and Aldabrachelys respectively) are sometimes given as examples of insular gigantism, they are now thought to represent the last remaining populations of historically widespread giant tortoises i.e. gigantism is an ancestral trait that occurred in the absence of insular selection pressures. The collection of differences in morphology, ecology, physiology and behaviour of insular species compared to their continental counterparts is termed Island syndrome.
After immigration, birds, and some reptiles or mammals, tend to become larger and predatory, showing relaxed intraspecific competition. For mammals, small species will increase in size and large species will decrease in size. This is referred to as the “island rule,” and is suggested to minimize energy expenditure.Other adaptations to life on islands include increased poikilothermy, relaxed anti-predator behavior, and reduced sexual selection in animals, and loss of herbivore defenses and reduced dispersal in plants.
=== Speciation ===
The formation of new islands and their isolation from the mainland provides many unoccupied niches for species to adapt to. Since immigration of predators and competitors is limited, many organisms are able to persist in these new niches. This results in a high occurrence of endemism, where species are unique to a localized area. For example, 50% of endemic bird areas are found on islands.
Endemism is often the result of adaptive radiation. Adaptive radiation is when a single species colonizes an area and rapidly diversifies to fill all of the available niches. A common example is the assemblage of finch species documented by Charles Darwin in the Galapagos Islands. Darwin’s finches exhibited adaptive radiation by evolving different beak sizes to exploit the diversity of seeds present on the different islands. Because the distributions of these populations are limited by their island habitats, they tend to have fewer individuals than their mainland counterparts and lower genetic variation. This, along with the behavioral and ecological factors mentioned above, makes island species more vulnerable to extinction.
=== Survival ===
The continued survival of species on islands depends on factors such as natural selection, genetic variation, natural disturbances (hurricanes, volcanic eruptions) and human-caused disturbances (introduced species, habitat loss). Human-caused disturbances tend to be the greatest cause of mortality, and understanding the causes of extinction facilitates conservation efforts.
=== Human impacts on island ecosystems ===
The movement of humans to islands has led to rapid extinction of native island species either from hunting, habitat destruction, or introduced species.
=== Hunting ===
Many large animals on islands have been hunted to extinction by humans. A well-known example is the dodo, once found on the island of Mauritius. It evolved to become large, flightless and docile, and was subsequently driven to extinction by humans and introduced predators.
=== Habitat destruction ===
The depletion of natural resources can have dramatic effects on island ecology. On Easter Island, the depletion of the forest by humans not only resulted in widespread loss of species, but also the collapse of the island civilization. Today there are over 500 million people on islands, all dependent on local resources either directly (traditional use) or indirectly (ecotourism revenue). Population growth and development result in heavy deforestation, pollution, and over-exploitation. Overharvesting of ocean fauna is particularly troubling as yields of coral reef fish species are an important food source for island populations.
=== Introduced species ===
Humans have contributed to globalization and decreased effective isolation of island communities, allowing for invasion of exotic species. This can have a profound effect on the native species. In Guam, the introduced brown tree snake ate nearly all of the native vertebrate species to extinction. Feral cats and dogs have also greatly diminished native vertebrate populations on islands, through both predation and disease. Introduced ungulates are another major threat, as they graze on native vegetation and can destroy entire forests. Exotic grasses can out-compete native understory species and increase the risk of fire. Lastly, social insects such as ants also cause major problems.Nonnative species introduced onto islands can have profound effects on an island's ecosystem, more so than nonnative species introduced to continental land (Platenberg). The higher impact of introduced and nonnative species on islands is largely a result of lower biodiversity levels (Platenburg et al). Biodiversity on islands is especially threatened by logging, hunting, fishing and plant gathering. However, islands’ vulnerability to introduced species is also due to agricultural, economic, and health differences as compared to continental land (Russel et al).
The smaller land area and population sizes of islands compared to continents create greater vulnerability to the impacts of introduced species (Russel et al). Introduced species negatively impact ecosystems through altered predator-prey interactions that can cause harm or even local extinction to native species populations (Towns et al). There are many examples of animal species such as birds, reptiles, and aquatic insects being harmed by the introduction of predators such as rats, cats, and ants. For example, seabirds on islands in Hawaii are impacted by non-native predators like barn owls and ants. At a colony in Hawaii, at least 20% of wedge-tailed shearwater eggs were taken by mynas, dark-plumaged birds of the starling family (Towns et al). Also in Hawaii, more than forty four introduced ant species, especially tropical fire ants, caused detriments to the growth of shearwater chicks, such as loss of tissue in their feet (Towns et al).
Other examples of high-impact species to island ecosystems are the Cuban treefrog and cane toad, which were introduced to the US Virgin Islands under various circumstances (Platenberg). The Cuban treefrog has been present in the USVI since arriving unintentionally on a cargo ship in the 1970s (Platenberg). The Cuban tree frog is known for its ability to survive under harsh conditions, and it is highly adaptable, as it will eat a wide variety of organisms (Platenberg). Native frog and anole lizard populations have declined, likely due to Cuban tree frog interference (Platenberg). In contrast to the accidental introduction of the Cuban treefrog, the cane toad was deliberately introduced to control agricultural pests (Platenberg). Similar to the Cuban treefrog, the cane toad is also omnivorous. Cane toad tadpoles compete for limited freshwater resources with the white-lipped frog, a native species, thus limiting their resources (Platenberg). In general, when the introduction of a nonnative species results in extinction, the ecosystem experiences losses in some trophic levels (Platenberg). For example, vertebrate herbivores that are prone to extinction change the ecosystem function in plant communities. This phenomenon is seen in New Zealand, where the loss of bird species may have changed dynamics in avian-induced vegetation communities and impacted abundances of forest plants (Platenberg).
Also in New Zealand, small mammalian predators such as rodents have little direct effect on vegetation but have greater effect on island faunas through extinction and displacement (Wood et al). Pacific rats, for example, were thought to be causing the local extinction of large, nocturnal ground-dwelling lizards, and they were assumed to have minimal effect on diurnal species, those that sleep at night, such as shore skinks (Wood et al). In places where Pacific rats were removed, however, shore skink populations rapidly changed, indicating that the rats’ impact has been underestimated (Wood et al).
The loss of a keystone species, a species that all other species in the ecosystem depend on such as seabirds, can also have significant effects (Towns). Seabirds are essential to the structure of the ecosystem because they transport large amounts of nutrients into ecosystems and burrow into soils, helping vegetation (Towns). However, since human settlement, seabird communities have been severely impacted on islands across the globe (Towns). While some exotic species may perform ecological roles similar to those of extinct species, there are many roles that cannot be fulfilled by other species. Therefore, similar exotic species do not offer complete replacement for extinct species in the community (Towns). Even if the number of species introduced to an island is roughly the same as the number of extinct ones, the ecological traits are not comparable enough to make up for losses (Towns).
=== Global warming ===
Global warming is emerging as a strong cause of species loss on islands. This can be due to sea level rise, the intrusion of salt water into freshwater habitats, or species inability to adapt to increasing temperatures and extreme weather events. Plant species are particularly susceptible. In more isolated areas, such as the Southern Ocean Islands, indirect effects such as invasive species and global warming can play a greater role in influencing populations than overexploitation, pollution and habitat loss.
=== Trophic cascades ===
Human activities and the introduction of non-native species often cause trophic cascades, where direct effects on one species result in indirect effects on other species in the food web. An example is on Santa Cruz Island of the California Channel Islands, where DDT poisoning reduced bald eagle populations. This, along with an abundance of introduced feral pigs for prey, allowed golden eagles to colonize the island and replace bald eagles. However, the golden eagles also ate native island foxes. Fox population levels decreased to near extinction, while skunk populations increased due to relaxed competition with foxes.
== Island conservation ==
=== Conservation on islands ===
Since island ecosystems are self-contained, it should be possible to mitigate many of the threats to species. Ecologists and managers are working together to prioritize areas for conservation and to quickly design and implement action plans. Not everything can be put into a reserve, so it is important to first compile pertinent information and prioritize areas of concern. Once an area has been chosen, managers must then acquire ownership and gain support. Local experts and indigenous populations should also be involved in this process. Having clearly defined goals will facilitate the many necessary interactions between people and agencies. Once a reserve is in place, managers can then practice adaptive management and do continued community education.
On land, island conservation focuses on the protection of species and their habitat. In some cases, conservation can be integrated with agricultural production. For example, the Acacia koa plantations and wooded pastures in Hawaii are anthropogenically altered ecosystems, yet allow connectivity between forest fragments and thus maintain higher diversity than would open pasture. Other directions include habitat restoration, and eradication of introduced predators, ungulates, and exotic plants (via hunting, removal or biological control).
In marine ecosystems, there has been an increasing establishment of “no-take” reserves. This allows for the reestablishment of native species, and also the augmentation of commercially harvested species. However, in both terrestrial and marine systems, these actions are expensive and do not always result in the desired outcomes. For example, some non-natives become keystone species and their removal can cause more harm than good to the ecosystem. To be more effective, managers of island ecosystems should share information and learn from each other’s mistakes.
=== Island restoration ===
Island conservation tends to focus on preservation of individual species and their habitats. However, many ecologists caution that ecological and evolutionary processes should be conserved as well. The conservation of island communities as a whole is closely linked to restoration.
Active restoration on islands can be done for both animal species (translocations, induced breeding) and plant species (reforestation). Creating goals for restoration can be challenging because it is often impossible to restore the ecosystem to its “historic” or “normal” state, if that state can even be clearly defined. Restoration is never complete, as ecological communities are always in a state of change.
=== Sustainable use ===
As resource depletion is a major issue on islands, the needs of human populations must also be taken into account. On many islands, scientists and managers are studying traditional practices of indigenous populations as potential conservation solutions. In some cases, limited-take systems that serve the community may provide a better alternative to fully closed protected areas, if there are not enough resources for proper enforcement. Public education plays an important role.
== See also ==
Disturbance (ecology)
Island biogeography
Island syndrome
Hawaiian honeycreeper conservation
Mammals of the Caribbean
Patch dynamics
Distance decay
Sky island
== References ==
== External links ==
Island Conservation
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Islands
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Island restoration
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The ecological restoration of islands, or island restoration, is the application of the principles of ecological restoration to islands and island groups. Islands, due to their isolation, are home to many of the world's endemic species, as well as important breeding grounds for seabirds and some marine mammals. Their ecosystems are also very vulnerable to human disturbance and particularly to introduced species, due to their small size. Island groups such as New Zealand and Hawaii have undergone substantial extinctions and losses of habitat. Since the 1950s several organisations and government agencies around the world have worked to restore islands to their original states; New Zealand has used them to hold natural populations of species that would otherwise be unable to survive in the wild. The principal components of island restoration are the removal of introduced species and the reintroduction of native species.
== Islands, endemism and extinction ==
Isolated islands have been known to have greater levels of endemism since the 1970s when the theory of island biogeography, formulated by Robert MacArthur and E.O. Wilson, was developed. This higher occurrence of endemism is because isolation limits immigration of new species to the island, allowing new species to evolve separately from others on the mainland. For example, 71% of New Zealand's bird species (prior to human arrival) were endemic. As well as displaying greater levels of endemism, island species have characteristics that make them particularly vulnerable to human disturbance.
Many island species evolved on small islands, or even restricted habitats on small islands. Small populations are vulnerable to even modest hunting, and restricted habitats are vulnerable to loss or modification of said habitat. More importantly, island species are often ecologically naive, that is they have not evolved alongside a predator, or have lost appropriate behavioural responses to predators. This often resulted in flightlessness, or unusual levels of tameness. This made many species susceptible to hunting (it is thought, for example, that moas were hunted to extinction in a few short generations) and to predation by introduced species. Some, such as the dodo, are thought to have become extinct because of the pressure of both humans and introduced animals. One estimate of birds in the Pacific islands puts the extinctions at 2000 species. Between 40 and 50% of the bird species of New Zealand have become extinct since 200 AD.
The field of island restoration is usually credited with having been started in New Zealand in the 1960s, but other smaller projects, such as the restoration of Nonsuch Island in Bermuda (which began in 1962) have been going on for almost as long. Nevertheless, the program undertaken by the Department of Conservation (DOC) is one of the largest in the world. It began on Cuvier Island, where ecologists removed stock, goats, feral cats and finally, in 1993, Pacific rats. The success of the project resulted in similar projects around New Zealand. The advantages to the DOC were considerable; in addition to protecting species endemic to smaller islands, like the magenta petrel, islands near the mainland, once restored, could act as habitat for species of birds that were unable to survive on the mainland. Species like the takahe, where the remaining wild population was at considerable risk from feral cats and dogs, could be moved to these islands to safeguard the species.
=== Eradication of introduced alien species ===
One important aspect of island restoration is the removal of invasive alien species. Since these species are most often the reason that native fauna and flora is threatened, their removal is essential to the restoration project. From 1673 until 2009, 786 successful invasive vertebrate eradication have been recorded and in the last few decades the frequency of eradications and the size of islands from which invasive vertebrates have been eradicated has increased. A definitive list of past island restoration efforts exists as the Database of Island Invasive Species Eradications. In addition a list of the current invasive species present on the world's islands exists as the Threatened Island DatabaseIslands are particularly suitable for restoration as once cleared of an introduced species they can be kept cleared of these species by virtue of being an island. Species removal is intensive and expensive, and methods used must be carefully chosen as to not create too much impact on non-target species. Feral cats, goats and three species of rats are among the most damaging species introduced to islands (Moors & Atkinson 1984). The differences in size, lifestyle and behaviour preclude the use of the same techniques for all of them, but with many species a range of techniques needs to be used in order to ensure success. Larger animals, such as goats and pigs, can be effectively hunted; in the case of Round Island, in Mauritius, all the goats were eliminated by a single marksman. On larger islands ecologists use a Judas goat, where a radio collared goat is released into the wild. This goat is then followed and groups it joins are removed. To remove cats a combination of techniques is needed: hunting, trapping and poisoning. Cats are more difficult to hunt than goats and pigs, requiring the use of experienced hunters and night hunting.
Trapping is ineffective for rats, given their sheer numbers, and the only method that works is poisoning, which can be delivered into the field by broadcasting (by hand or from the air) or by the maintenance of bait stations. This method has been employed around the world, in the Falkland Islands, in the tropical Pacific, and off New Zealand, where over 40 islands have been cleared. This method is not without problems, especially if the rats share the island with other, native species of rodent that might take the bait as well, as has happened on Anacapa Island in the Channel Islands and Rat Island (Hawadax) in the Aleutian archipelago. In the Pacific poison intended for rats was taken by land crabs instead; the crabs were not affected by the poison but frustrated attempts to clear the rats.
The removal of invasive weeds is, in most cases, more difficult than removing animal species. One such eradication was that of sandbur, Cencrus echinatus, an introduced grass on Laysan. The grass, introduced to Laysan around 1961, had taken over 30% of the island by 1991, displaced the native bunchgrass, and reduced the breeding habitat of two endemic threatened species, the Laysan duck and Laysan finch, as well as those of several seabirds. The removal took ten years, with controlled spraying for the first year, then individual removal of plants, then, when few plants were being found, sifting of the sands around plants to remove seeds. The cost of the eradication program was $150,000 per year.
Invasive vertebrate eradication has many benefits besides conservation of species and has been found to align with 13 UN Sustainable Development Goals and 42 associated targets encompassing marine and terrestrial biodiversity conservation, promotion of local and global partnerships, economic development, climate change mitigation, human health and sanitation and sustainable production and consumption.
==== Strategies ====
There are three strategies to reduce the numbers of the introduced animals in order to lighten the problems caused by them: exclusion, control, and eradication.
Exclusion is removal of introduced species in limited areas and focused on a local impact.
Control has a meaning of mitigation by reducing the numbers of introduced species down to ecologically and economically less harmful level. Since it is not complete wiping out strategy, this has to be taken constantly and repeatedly. This strategy is said to be feasible but less cost effective due to its incompleteness.
Eradication is the complete removal of all the individuals of the population, down to the last potentially reproducing individual, or the reduction of their population density below sustainable levels (J. H. Myerset al., 2000). For islands, it is usually the best strategy as it gives permanent effects, which potentially means most cost effective. However, it is still logistically and economically high cost. Also, this strategy is sometimes hard to accomplish depending on the environment of island and the alien species. Island Conservation exclusively focuses on the eradication of invasive vertebrate species from islands. Up until 2021, the organization had deployed teams to protect 1,195 populations of 487 species and subspecies on 64 islands.
==== Methods ====
Fencing is used for excluding the alien mammals. This method intends to limit the area for the mammals before control or eradication.
Shooting is often used for large animals to control them. This method has meanings of gaining food supply and recreation. It requires accessibility in the field and experience for the hunters. Also, to maintain the effect, it requires good amount of manpower for long time, so it can be costly.
Trapping is designed for medium-sized mammals which are hard to shoot at. This method is usually only for reduction not eradication. The advantage of this method is that it can be selective since it is possible to exclude or reduce the possibility of trapping native animals. However, trapping requires limited area to cover and limited population to capture.
Poisoning is very effective for small species. However, there are some disadvantages of this method. It is possible that untargeted animals take the poison. It is also necessary to consider the secondary poisoning that other animals are affected by poisoned species. This method can be costly if the area to cover is large.Pathogen Introduction (parasitism) is one of the biological methods to eradicate alien species. It is very effective for limited species, but the viruses and bacteria need to be specified clearly for use.Predator introduction is another biological method to eradicate the introduced species. It is less costly and environmentally clean, but it can cause greater problems, because it is possible that the introduced predator targets the native animals instead of alien species and its existence and its parasites can be new problems.Competitor introduction is also a biological method to eradicate introduced carnivores. It can be very effective with good amount of information. In the end, the competitor has to be removed as well.
Virus vectored immune-contraception is one of the newest method that is to infect introduced animals with genetically engineered viruses. This method is considered environmentally clean, low cost, selective, and ethical. However, it is not fully operational and the effect comes slowly.
=== Restoration of former habitat ===
In many cases the removal of introduced species is sufficient to allow a return to a pre-disturbance state, but generally active management, often in the form of replanting native flora and reintroduction of extirpated fauna is needed to achieve restoration goals. Planting of native species helps to replenish species that were either grazed or out competed. Species of animal can be translocated either from existing populations, or from captive bred populations. These reintroductions need to be carefully managed, particularly in the case of endangered species, where the potential benefits need to be weighed against the possibility of failure. Not all translocations succeed, and it may be necessary to help the reintroduced animals along with supplementary feeding or other kinds of management.
One other important aspect of restoration is prevention, that is, keeping invasive species from returning to a cleared island. This can be achieved by restricting access to the island in question (reducing possible instances of invasion) to more stringent quarantine methods. For example, in order to prevent invasive weeds from returning to Laysan, people working on the island must bring entirely new clothes to the island, which must be frozen prior to arrival.
== Opposition to island restoration ==
Prior to the initial efforts to remove rats from New Zealand's offshore islands there was a great deal of skepticism as to the feasibility of island restoration amongst ecologists and conservation workers. However, as the techniques have improved and larger islands have been restored, most of the initial criticisms from within the field have been dropped, in particular as the costs of eradication are often much lower than continuous pest control.
Outside of the field of conservation there has been some opposition from other interested groups, particularly from the animal rights movement, which contends that the welfare of the pests in question is not adequately addressed in island restoration plans. Because a broad spectrum of pest removal techniques needs to be used, including leg traps, animal rights campaigners accuse ecologists of cruelty, and indifference to non-targeted species that also take bait or are trapped, and suggest that more humane methods such as capture and sterilization be used instead (something those working in island restoration contend would be too expensive, and potentially ineffective as in Kangaroo Island koalas). Some also defend the rights of the introduced species to exist as well. Others, including scientists affiliated with the animal rights movement, accept that when the choice is between the future of a species and a population of pests, the future of a species must take priority (with the caveat that the extermination is conducted as humanely as possible).
Opposition to island restoration has not led to the abandonment of many projects but has delayed several, particularly through court action. Groups sometimes adopt different approaches; opponents of hedgehog removal in the Outer Hebrides offered bounties for live hedgehogs removed from the islands and relocated in their natural habitat. Invasive plants can also generate strong feelings. The removal of Eucalyptus trees from Angel Island in San Francisco Bay faced considerable opposition.
== Island restoration projects ==
Island restoration has been attempted in many countries since the 1960s, and has met with varying degrees of success. The following examples highlight some of the factors that influence projects. A comprehensive list of projects can be found on the Database of Island Invasive Species Eradications.
=== Round Island ===
Round Island (Île Ronde in French) is a tropical island 22.5 kilometres north of Mauritius, with an area of 1.69 square kilometres and a maximum elevation of 280 metres. Compared to other Mascarene islands and islets, Round Island remained relatively pristine until goats and rabbits were introduced in the 19th century (goats were introduced between 1846 and 1868, whilst rabbits were present in large numbers before 1810). These herbivores, along with other factors, such as sporadic logging and frequent cyclones, led to the eventual dwindling of the island's forests and dependent fauna. In turn, this led to soil erosion by wind and rain, impeding forest regeneration, acting as a positive feedback mechanism that caused rapid deforestation of the island. In 1957, however, Round Island was officially made a nature reserve, and in 1979 and 1986 was rid of goats (shooting) and rabbits (poisoning), respectively, after several unsuccessful attempts.Since removal of the introduced herbivores, the Round Island plant community has recovered dramatically. This is especially stark for three of the endemic tree species, Latania loddigesii, Pandanus vandermeerschii and Hyophorbe lagenicaulis, which constituted a large portion of the Round Island forest historically. This has led to six reptile species (five of which were critically endangered) recovering in tandem with the plant community; these are the skinks Leiolopisma telfaririi and Scelotes bojerii, the geckos Phelsuma guentheri, P. ornata and Nactus serpensinsula, and the snake Casarea dussumerii.The Round Island restoration program represents one of the longest-running projects of its kind in the world, since its conservation status was confirmed in 1957. Much of the current conservation work on Round Island is conducted by the Mauritian Wildlife Foundation and Durrell Wildlife Conservation Trust and revolves around maintaining soil levels, reforestation of the island, and eradication of remaining invasive plants and invertebrates.
=== Aleutian Islands ===
The Aleutian Islands, prior to the 18th century, lacked any terrestrial predators, but from the mid-18th century Arctic foxes were introduced to act as a source for the fur trade, a practice that continued into the early 20th century. This introduction decimated the birds of the chain, particularly seabirds like the whiskered auklet. The reduction in seabirds, in turn, had effects on the ecology of the islands, as many of the plants were dependent on the guano from nesting birds acting as a fertilizer. In the early 1950s managers of the Aleutian Islands Reservation became aware of the damage, and an eradication program began. Since then over 80 islands have been cleared of non-native foxes (only six islands remain) and bird populations have rebounded. Whiskered auklets, which numbered 25,000 in 1974, had increased to 116,000 in 2003.
=== Campbell Island ===
Campbell Island is a sub Antarctic island 700 km south of New Zealand that became infested with rats in the 19th century. Several endemic birds, including the Campbell teal and Campbell snipe, only survived on small rocky islets just off the island, and the populations were perilously low. Several teals were taken into captivity for ex-situ conservation, but once they had bred in captivity there was no-where else to return them to until the island was cleared of rats. The DOC's plan to remove rats from the island was one of the most ambitious attempted, as the island was so remote, the rat populations had the highest density of rats anywhere in the world, the weather treacherous and, at 113 km2, it was the largest island at that point where eradication had been attempted. The poison had to be dropped in the winter, to minimize disturbance to nesting seabirds and reduce the chance of bird strike for the pilots. After several experiments, the eradication began in 2001. In 2003 trackers with dogs were unable to find any rats. Soon after the island was cleared it was possible to return the teals to the island. Snipe have self-reintroduced to the island and have begun breeding.
=== South Georgia ===
Rats, brought to South Georgia Island as stowaways on sealing and whaling ships in the late 18th century, have caused much damage to native wildlife, destroying tens of millions of ground-nesting birds’ eggs and chicks. While previously the island's glaciers formed a natural barrier to the spread of rats, these glaciers are now slowly melting as the climate warms. In 2011, scientists instituted a four-year programme to entirely eradicate the rats and mice, in what would be by far the largest rodent eradication attempt in the world to date. The project was led by zoologist Anthony Martin of The University of Dundee who stated, "This is a man-induced problem and it's about time that man put right earlier errors." In July 2013, the success of the main phase of the extermination of the rats, which took place in May that year, was announced. 180 tonnes of rat poison, brodifacoum, were dropped over 70% of the island, in what was the world's largest ever operation of this kind. Another 95t of rat poison was planned to be dropped by three helicopters in January 2015. In June 2015 the eradication programme concluded, apparently successfully, with the island believed "very likely" to be rat free. Monitoring will continue for a further two or three years.
== Notes ==
== References ==
Courchamp, F., Chapuis, J., and Pascal, M. (2003). Mammal invaders on islands: impact, control and control impact. Cambridge Philosophical Society. 78, 347-383.
Myers, J. H., Simberloff, D., Kuris, A. M. & Carey, J. R. (2000). Eradication revisited : dealing with exotic species. Trends in Ecology & Evolution 15, 316–320.
== Further reading ==
Atkinson, I A E, (1988). Presidential address: Opportunities for Ecological Restoration. New Zealand Journal of Ecology 11: 1-12
Flint, E. & Rehkemper, G. (2002) Control and eradication of the introduced grass, Cenchrus echinatus, at Laysan Island, Central Pacific Ocean. Turning the tide: the eradication of invasive species (proceedings of the international conference on eradication of island invasives) (Occasional Paper of the IUCN Species Survival Commission No. 27. Veitch, C. R. and Clout, M.N., eds).
Kettmann, M. ( April 29, 2003) Death for Life on Anacapa island, The Santa Barbara Independent
Moors, P.J.; Atkinson, I.A.E. (1984). Predation on seabirds by introduced animals, and factors affecting its severity.. In Status and Conservation of the World's Seabirds. Cambridge: ICBP. ISBN 0-946888-03-5.
Nogales, Manuel et al. (2004). A review of feral cat eradication on islands. Conservation Biology. 18 (2), 310-319.
Williams, J.C., Byrd G.V.& Konyukhov, N.B. (2003) "Whiskered Auklets Aethia pygmaea, foxes, humans and how to right a wrong." Marine Ornithology 31: 175-180.
Wingate, D.B. (1985) The restoration of Nonsuch Island as a living museum of Bermuda's precolonial terrestrial biome. In Conservation of Island Birds. ICBP Technical Publication. ISBN 0-946888-04-3
THE RAT ISLAND RAT ERADICATION PROJECT: A CRITICAL EVALUATION OF NONTARGET MORTALITY. PREPARED FOR ISLAND CONSERVATION THE NATURE CONSERVANCY and the U.S. FISH AND WILDLIFE SERVICE, ALASKA MARITIME NATIONAL WILDLIFE REFUGE. PREPARED BY THE ORNITHOLOGICAL COUNCIL. Final report issued December 2010.
US Fish and Wildlife Service, Office of Law Enforcement, Report of Investigation #2009703127R001
== See also ==
Island ecology
Restoration ecology
== External links ==
Database of Island Invasive Species Eradications (DIISE)
Threatened Island Biodiversity database (TIB)
USDA - APHIS - Wildlife Services
Island Conservation
Conservación de Islas
New Zealand Department of Conservation Ecological Restoration
IUCN Proceedings of the International Conference on Eradication of Island Invasives
UC Santa Cruz: Impact of Foxes in Alaska
BBC News: New Zealand's pest eradication on islands
UK SNH Uist Wader Project: impact of hedgehogs on wading bird breeding success
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Islands
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Island syndrome
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Island syndrome describes the differences in morphology, ecology, physiology and behaviour of insular species compared to their continental counterparts. These differences evolve due to the different ecological pressures affecting insular species, including a paucity of large predators and herbivores as well as a consistently mild climate.
== Ecological driving factors ==
Reduced predation. Island ecosystems cannot support a sufficient biomass of prey in order to accommodate large predators. This largely relieves prey species of the risk of predation, which mostly removes the selection pressure for morphologies, ecologies and behaviours that help to evade large predators.
Reduced biodiversity. Insular ecosystems tend to comprise large populations of a limited number of species (a state termed density compensation), therefore, they exhibit low biodiversity. This results in reduced interspecific competition and increased intraspecific competition.
Reduced sexual selection. There is also reduced sexual selection in insular species, which is especially prominent in birds which lose their sexually dimorphic plumage used in sexual displays.
Reduced parasite diversity. Finally, there is reduced parasite diversity in insular ecosystems which reduces the level of selection acting on immune-related genes.
== Features of island syndrome in animals ==
=== Body size ===
Interspecific competition between continental species drives divergence of body size so that species may avoid high levels of competition by occupying distinct niches. Reduced interspecific competition between insular species reduces this selection pressure for species to occupy distinct niches. As a result, there is less diversity in the body size of insular species. Typically small mammals increase in size (for example fossa are a larger insular relative of the mongoose) while typically large mammals decrease in size (for example the Malagasy hippopotamuses are smaller insular relatives of continental hippopotamuses). These are examples of insular gigantism and insular dwarfism respectively. This observed effect is called Foster's rule. Conversely, birds and reptiles tend to exhibit insular gigantism, exemplified by the moa, cassowary and Komodo dragon.
Although the giant tortoises of the Galápagos Islands and the Seychelles (the Galápagos tortoise and Aldabrachelys respectively) are sometimes given as examples of insular gigantism, they are now thought to represent the last remaining populations of historically widespread giant tortoises. The remains of tortoises of similar or larger size have been found in Australia (Meiolania), southern Asia (Megalochelys), Madagascar (Aldabrachelys), North America (Hesperotestudo) and South America (Chelonoidis). The extant giant tortoises are thought to persist only in a few remote archipelagos because humans arrived there relatively late and have not heavily predated them, suggesting that these tortoise populations have been less subjected to overexploitation.
=== Locomotion ===
Since insular prey species experience a reduced risk of predation, they often lose or reduce morphologies utilised in predator evasion. For example, the wings of weevils, rails and pigeons have become so reduced in insular species that many have lost the ability to fly. This has occurred in several ratites including the kiwi and the cassowary as well as in the dodo and the kakapo after invading island habitats. The extinct moa of New Zealand exhibit the most extreme known example of insular wing reduction; there is no osseous evidence of even vestigial wings and the pectoral girdle is reduced to a scapulocoracoideum which would be unable to bear a forelimb as it lacks a glenoid fossa. Therefore, it is the only bird known to have completely lost its wings after a shift to insularity. Loss of flight allows birds to eliminate the costs of maintaining large flight-enabling muscles like the pectoral muscles and allows the skeleton to become heavier and stronger. Insular populations of barn owl have shorter wings, representing a transitional stage in which their capacity for flight is being reduced.
=== Adaptive coloration ===
Due to the reduced sexual selection of insular species, they tend to exhibit reduced sexual coloration so as to conserve the energy that this demands. Additionally, the low biodiversity of insular ecosystems makes species recognition less important so species-specific coloration is under less selection. As a result, insular bird species often exhibit duller, sexually monomorphic plumage.Several insular species acquire increased melanin colouration. Male white-winged fairywrens living on mainland Australia exhibit a blue nuptial plumage, whereas two island subspecies (Malurus leucopterus leucopterus from Dirk Hartog Island and Malurus leucopterus edouardi from Barrow Island) exhibit a black nupital plumage. A subspecies of the chestnut-bellied monarch endemic to the Solomon Islands, Monarcha castaneiventris obscurior, exhibits polymorphism in plumage color: some birds are black with a chestnut-colored belly while others are completely melanic. The frequency of the melanic phenotype increases on smaller islands, even when the relative proximity of the islands is accounted for.
=== Reproduction ===
High levels of intraspecific competition between offspring selects for the very fittest individuals. As a result, insular parents tend to produce fewer offspring so that each offspring receives greater parental investment, maximising their fitness. Lizards endemic to island ecosystems lay smaller clutches that give larger offspring compared to continental lizards of a similar size. Because of increased frequency of laying in insular lizards, continental and insular lizards produced offspring at a comparable rate.
=== Brain size ===
The expensive tissue hypothesis suggests that tissues with a high metabolic demand like the brain will become reduced if they confer little selective advantage and so do not help to increase food intake. The paucity of large predators means that insular species can afford to become slower and less alert without suffering from massively increased predation risk. As such, reduction in relative brain size is often seen in insular species as this reduces basal metabolic rate without increases in predation risk. For example, the endocranial volume of the extinct Malagasy dwarf hippos is 30% less than that of an equally sized continental ancestor. Similarly, the early human, Homo floresiensis, had a brain of similar size to that of the significantly earlier Australopithecus specimens from mainland Africa and 3.4 times smaller than that of Homo sapiens which evolved later (see Evolution of human brain size).
=== Poikilothermy ===
Due to low predation risk, insular prey species can afford to reduce their basal metabolic rate by adopting poikilothermy without any significant increase in predation risk. As a result, poikilothermy is far more common in island species.
=== Behaviour ===
Due to lack of predation, insular species tend to become more docile and less territorial than their continental counterparts (sometimes referred to as island tameness). Deer mice, song sparrows and bronze anoles all have smaller territories with greater overlap compared to their mainland conspecifics. They are also more tolerant to intruders. Falkland Island foxes and Tammar wallabies have both lost an innate fear of large predators including humans.
== In parasites ==
The nematode parasite Heligmosomoides polygyrus underwent niche expansion (by invading new host species) and a reduction in genetic diversity after invading ecosystems in seven western Mediterranean islands. The loss of genetic diversity was related to the distance between the contemporal population and the mainland origin.
== In plants ==
=== Plant structure ===
Plant stature and leaf area both follow the pattern of insular mammals, with small species becoming larger and large species becoming smaller in island populations. This may be due to reduced interspecific competition which would decrease the ecological drive for plants to occupy separate niches. Due to reduced biomass of large herbivores, several island plants lose protective spines and thorns as well as decreasing the amounts of defensive chemicals produced. The improbability of island fires also results in a loss of fire-resistance in bark, fruits and cones. Insular woodiness, the evolutionary transition from herbaceousness toward woodiness, is a very common phenomenon among island floras.
=== Reproduction and dispersal ===
Due to a lack of dedicated pollinators on remote islands, insular plants often use small, inconspicuously colored and easily accessible flowers to attract a range of alternative pollinator species. Self-pollination is also more commonly used by insular plant species, as pollen does not have to travel so far to reach a receptive ovule or stigma.
Seeds exhibit insular gigantism, becoming predominantly larger than mainland seeds, which is thought to improve mortality at sea during dispersal.
== Consequences of island syndrome for conservation ==
The relaxed predation risk in island ecosystems has resulted in the loss of several adaptations and behaviours that act to evade or discourage predation. This makes insular species particularly vulnerable to exploitation by alien species. For example, when humans first introduced dogs, pigs, cats, rats, and crab-eating macaques to the island of Mauritius in the 17th century, they plundered dodo nests and increased interspecies competition for the limited food resources. This ultimately resulted in the dodo's extinction. The limited resources in island ecosystems are also vulnerable to overexploitation if they are not managed sustainably.
== Hațeg Island ==
Hațeg Island was a large offshore island in the Tethys Sea of the Late Cretaceous and is often called "The Island of the Dwarf Dinosaurs" on account of the extensive fossil evidence that its native dinosaurs exhibited island dwarfism. The island's native titanosaur, Magyarosaurus dacus, had a body mass of only 900 kilograms (2,000 lb) while mainland titanosaurs like Patagotitan could reach up to 69 tonnes (76 tons). The pterosaur Hatzegopteryx took over the position of apex predator of Hațeg Island in the absence of any hypercarnivorous dinosaurs and likely hunted juvenile dwarf dinosaurs or even adults of the smaller species. Based on its robust jaw and cervical vertebrae, Hatzegopteryx is thought to have hunted in a similar manner to modern storks by attacking prey that are too large to swallow whole. Its wingspan is estimated to have reached up to 10 to 12 metres (33 to 39 ft), making it one of the largest pterosaurs to have ever lived. As such, it is a potent example of island gigantism, in this case to fill the otherwise empty niche of apex predator. Balaur bondoc was originally classified as a dromaeosaurid dinosaur based on its retractable toe claws. Its forelimbs appeared to be too short and stocky for it to be a basal avialan, however, phylogenetic analysis later confirmed that Balaur was indeed a basal member of Avialae, a clade that includes modern birds. Its limbs were clearly incapable of powered flight and so Balaur is yet another example of the secondary loss of flight after invading an island niche, similar to insular species of barn owls and ratites as well as the extinct moa and the dodo (See Insular reduction in flight capacity).
== Reversed island syndrome ==
The term "reversed island syndrome" (RIS) was first used by Pasquale Raia in 2010 to describe the differences in morphology, ecology, physiology and behaviour observed in insular species when population density is either low or fluctuating. This results in stronger natural selection and weaker intraspecific selection, leading to different phenotypes compared to the standard island syndrome.
RIS was first described in a population of Italian wall lizard endemic to the Licosa Islet where the unpredictable environmental conditions and highly fluctuating population density have selected for aggressive behaviour and increased reproductive effort. The male lizards exhibit elevated α-MSH levels relative to mainland populations, which increases the basal metabolic rate, strengthens immune responses, produces darker blue coloration and raises 5α-dihydrotestosterone levels. The latter improves male reproductive success by increasing the likelihood of winning sexual conflicts over females and augmenting sperm quality. Females produce similar numbers of eggs compared to mainland populations but the eggs of insular females are significantly heavier, reflecting increased reproductive effort. The unpredictable conditions produce high mortality rates so adults invest more effort into current broods since they are less likely to survive to produce subsequent broods i.e. there is low interbrood conflict.
== References ==
== See also ==
Island ecology
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Islands
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Little Shell Island
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Little Shell Island is a small island 2km east of Sidney, British Columbia, Canada. It is part of the Gulf Islands. The island is approximately 1 acre (0.4 hectares) in size. It is part of the Little Group of islands near Sidney and has a rich variety of wildlife. It is named after its beach, which is composed of broken seashells.
In 2021, it was put up for sale for $1.1 million.
== References ==
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Islands
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Island mentality
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Island mentality is the notion of isolated communities perceiving themselves as exceptional or superior to the rest of the world. This term does not directly refer to an island or other geographically confined society, but to the cultural, moral, or ideological superiority of a community or a person that lacks social exposure to the outside world. Island mentality can be characterized by narrow-mindedness, ignorance, or outright hostility towards any artifact (concept, ideology, lifestyle choice, art form, etc.) originating from outside the geographic area inhabited by the society.
The term "island mentality" is also used in some psychological research to describe individuals who dislike or have problems with relating to others, and then live as loners or "islands". This concept (in which people may feel inferior, afraid, or alone) is unrelated to the above terminology.
== See also ==
Ethnocentrism
Exceptionalism
Galápagos syndrome
Groupthink
Light unto the nations
Not invented here
Shtetl
Siege mentality
== References ==
Israel and Pacific republics, united by an island mentality
Desert the island mentality
Ditch the island mentality
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Islands
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Port-Christmas
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Port-Christmas is a natural and historical site on the Kerguelen Islands, located at the northern tip of the main island, on the east coast of the Loranchet Peninsula. It covers the bottom of Baie de l'Oiseau, the first shelter for sailors approaching the archipelago from the north, and is easily identifiable by the presence at the entrance of a natural arch, now collapsed, known as the Kerguelen Arch.
It was here, in 1774, that the explorer Yves Joseph de Kerguelen de Trémarec took possession of the island on behalf of King Louis XV of France. However, the name of the island, Christmas Harbour, was given by James Cook, whose ships anchored in the bay on Christmas Day back in 1776, during his third circumnavigation. The name appears in some French translations or fictional works such as le Havre de Noël or Port-Noël.
Considered to be a safe haven, in the 19th century it regularly welcomed the ships of seal and whale hunters, mainly from Nantucket, who scoured the southern seas and islands. The site is also occasionally used as a research station for geomagnetism investigations.
Descriptions of these landscapes by explorers in their travelogues inspired great writers, starting with Edgar Allan Poe (1838), followed by Jules Verne (1897), who incorporated them into their adventure novels, then Valery Larbaud (1933) and Jean-Paul Kaufmann (1993), among others, in their more personal works.
== Toponymy ==
The name "Port-Christmas" was established by Raymond Rallier du Baty in 1908 to designate the most isolated part of Baie de l'Oiseau, as shown on the 1⁄228000 map published in 1922. The Commission territoriale de toponymie des Terres australes françaises (TAAF Territorial Commission) upheld this designation when the 1⁄100000 IGN map was published in 1973. It also extended the name to the area between the beach and Lake Rochegude, location to a secondary scientific station.This now-official toponymy puts an end to almost two centuries of debate between the name given to the whole bay by Kerguelen, "Baie de l'Oiseau", and the one chosen by Cook, "Christmas Harbour".
Indeed, during his second expedition, Yves Joseph de Kerguelen de Trémarec called this bay after L'Oiseau, the frigate he sent there in January 1774 to do reconnaissance. Almost three years later, on December 25th 1776, the ships HMS Resolution and HMS Discovery anchored in the same location. Captain Cook, in command of the expedition, was well aware of the French navigator's earlier discovery, but was not yet aware of the details, nor that the bay had already been named. He decided to celebrate the holiday's festivities by giving this "Christmas haven" the English name of Christmas Harbour.The predominantly Anglo-American presence of the archipelago in the 19th century, along with its literature, favored the use of the latter name.
However, when France decided to reaffirm its sovereignty by sending the French aviso ship l'Eure in 1893 to perform a new take-over ceremony, Baie de l'Oiseau formally reverted to its original name.
In the end, the current consensus, instituted by Rallier du Baty, which "semi-francizes" Christmas Harbour as Port-Christmas and reserves its denominations for a particular area of Baie de l'Oiseau, allows us to respect Kerguelen's former discovery while preserving the historical trace of Cook's passage.
== Geography ==
=== Location ===
From the permanent base at Port-aux-Français, located 115 km to the southeast, Port-Christmas is one of the most isolated and inaccessible areas of the archipelago. Given its distance and, in particular, its mountainous topography, the site is almost never reached by land. It can, however, be reached by sea after sailing at least 100 nautical miles (190 km). Baie de l'Oiseau, at the base of which the site is located, forms the first indentation at the northeastern end of the Loranchet peninsula. The bay is closed off to the north by the Cape-Haïtien and to the south by Kerguelen Arch.
Port-Christmas is towered over by Table de l'Oiseau (403 m) to the north and Mount Havergal (552 m) to the south.While most of the bay's shores are rocky and often steep, the bottom is occupied by a 350-meter-long black sand beach, formed by the erosion of the surrounding basalt rocks. Here, a stream flows into the sea, after collecting both stormwaters from Mount Havergal and drainage tunnel waters from Lake Rochegude. This lake, located approximately 500 m from the shore at an altitude of 40 m, marks the barrier separating Port-Christmas from Baie Ducheyron to the west.The anchorage at Port-Christmas is 11 meters deep (6 fathoms). It offers a relatively safe haven for sailors who frequent this particularly turbulent part of the ocean caused by the Roaring Forties.
=== Geology ===
The geological environment of Port-Christmas, like that of practically the entire Loranchet Peninsula, is dominated by trap-rocks, terraced basaltic piles formed by the superimposition of lava outpourings around twenty-eight to twenty-nine million years ago.At various points in the bay, between the hard stratum, a few small coal seams emerge. British explorer James Clark Ross noted this as early as 1840. He also noted the presence of fossilized trees, the first of their kind to be spotted in the archipelago. These petrified woods, or simply lignites, found at Port-Christmas and Mount Havergal, mainly belong to the conifer tree families known as Araucariaceae and Cupressaceae, more specifically the Araucarites, Cupressinoxylon, and Cupressoxylon genera, which are similar to those found today in the southernmost regions of the Southern Hemisphere. They bear witness to widespread ancient vegetation and past climates that were milder, or at least did not undergo intense glacial periods.
=== Highlights ===
From Port-Christmas, the sight of the pillars of the Kerguelen Arch is a must. As soon as the archipelago was discovered, Kerguelen mentioned the imposing rocky arch located at the tip of the southern rim at the entrance to Baie de l'Oiseau. It rises to over 100 meters. Named "le Portail" by Kerguelen, then "Arched-Rock" by James Cook, the arch collapsed between 1908 and 1913, leaving only its two basalt columns standing.Port-Christmas also has the geographical distinction of being one of the only land-based antipodes with the United States territory. It corresponds to Kevin, a township in Toole County, in the state of Montana, near the border with Canada.
== Natural environment ==
When the first navigators landed in the archipelago, they were struck by the abundance of a rich variety of birds. On the Port-Christmas shore itself, Kerguelen's lieutenants, like James Cook, noted the presence of "penguins". A nesting colony of king penguins is still found there today, one of the smallest on Kerguelen with just forty breeders. Elephant seals, known at the time as "sea lions", also frequent the beach.Fishing, on the other hand, was disappointing as the net Cook had thrown into the sea brought back only half a dozen fish. Recent samples show that the fish in the area belong to the Channichthyidae family, or sometimes to the species Zanclorhynchus spinifer, the Antarctic horsefish, of the Congiopodidae family. The beach drop-offs at Port-Christmas are notable for their abundance of soft corals (Onogorgia nodosa), and the giant seaweed Macrocystis pyrifera forms dense seagrass meadow.Conversely, terrestrial vegetation is poorly developed. While early records describe a verdant, albeit short and treeless, coastal landscape covered with grasses (Gramineae), azorella, and Kerguelen cabbage, the colonization of the entire main island by rabbits has since led to a considerable weakening of plant formations, which are often reduced to a meager meadow of Acaena magellanica.
Generally speaking, the fauna and flora are in accordance with that to be found in Baie de l'Oiseau and more widely on the main island of the archipelago, known as La Grande Terre.The entire Port-Christmas area is part of the Réserve naturelle nationale des Terres australes françaises, which, since 2019, has been classified as World Heritage under the name of "French Southern and Antarctic Lands".
Like the majority of the archipelago, its terrestrial sector benefits from the "classic" protection regime. The area is closed to the introduction of any new animal or plant, any disturbance of living communities, any industrial, commercial or mining activity, and any biological or mineral extraction, with the exception of rare exemptions that may be granted by the Reserve's management or for scientific research purposes. Access to the site is possible, but is regulated and subject to authorization.The marine section, like all the territorial waters of the Kerguelen Islands, is included in the "zone de protection renforcée marine". Any disturbance of the natural environment is prohibited, except for scientific activities duly approved by the authorities. All professional and recreational fishing is prohibited, with no exceptions.
== History ==
The first sighting of the islands dates back to the second expedition of Yves Joseph de Kerguelen de Trémarec, aboard the Roland, a 64-cannon vessel, with an escort of two smaller ships, l'Oiseau and la Dauphine. The expedition reached the coast of Grand-Terre [sic] on December 14th, 1773, but adverse weather conditions prevented them from disembarking. During the few days la Dauphine was separated from the group, Ferron du Quengo, commander of the Corvette, spotted the entrance to a bay around December 20th, 1773, but was unable to gain entry. On December 25th, 1773, Kerguelen delegated to l'Oiseau and la Dauphine the task of trying to land there. The commander of l'Oiseau, Monsieur de Rosnevet, mapped out the bay and named it Baie de l'Oiseau, after his frigate. But it wasn't until January 6th, 1774, that he managed to send his lieutenant Henri Pascal de Rochegude ashore in a longboat. The latter attached a bottle to a prominent rock, containing a formal takeover statement:« Ludovico XV. galliarum rege, et d. de Boynes regi a Secretis ad res maritimas annis 1772 et 1773. »The fact that the years 1772 and 1773 are mentioned, even though the official parchment was not issued until 1774, means that the land had already been discovered and that this formal takeover merely reiterated the first expedition by Kerguelen, who was led by Lieutenant Charles-Marc du Boisguéhenneuc on February 14th, 1772, to "Baie du Lion-Marin" (now known as Anse du Gros Ventre), forty leagues to the south. James Cook, who stopped off in the archipelago on his "third voyage", dropped the anchors of his ships Discovery and Resolution on Christmas Day, 1776. He called the place Christmas Harbour and realized the previous presence of the French when he found the message they had left. He added a mention of his own berthing and a vintage silver coin, relocating the bottle under a cairn. The British explorer notes the optimal anchorage and water provisioning conditions. The ship's surgeon, William Anderson, noted both the presence of Kerguelen cabbage (Pringlea antiscorbutica), which could be used to combat the scurvy often suffered by crews on long voyages, and the abundance of "oil resources". It was also from Christmas Harbour that Cook thought of naming the archipelago the "Islands of Desolation", before paying tribute to his first French discoverer by naming them after himself, albeit somewhat mischievously: « I would have called them the Islands of Desolation, if I didn't want to deprive Monsieur de Kerguelen the honor of giving them his name. »The expedition set off again on December 31st to explore the surrounding eastern coasts all the way to the present-day Gulf of Morbihan, which James Cook named "Royal Sound".
It only took a few years for the previously untouched Desolation Islands to become a coveted land. The first expedition to hunt marine mammals by American ships from the island of Nantucket was documented as early as 1792. The interest of the Americans in undertaking campaigns in the southern seas was even greater, considering that the British had forbidden them to hunt in the northern hemisphere. Christmas Harbour, with its safe anchorage, became a popular stopover throughout the nineteenth century, as it was easy to reach, even if it didn't offer the best shelter in poor weather. In the early 1820s, American explorer and sealing captain Benjamin Morrell (1795–1839) made it his main anchorage. The Kerguelen archipelago was frequented by whalers and sealers until 1909 (with a highpoint between 1840 and 1870).
In 1840, British explorer James Clark Ross anchored at Port-Christmas for 68 days, between May and July, as part of a major scientific expedition around the world and towards the poles, with the primary objective of studying geomagnetism. Two temporary observatories were built at the far end of the bay, one dedicated to astronomical observations, and the other to the study of terrestrial magnetism. Every day, at a fixed time, regardless of the weather, magnetism readings were taken simultaneously with a complementary station located almost antipodally in Toronto, Canada. Ross's mission brief included a long series of other physical observations to be carried out: meteorological, oceanographic, hydrographic, as well as a naturalistic component to which the expedition's surgeons, Robert McCormick, Joseph Dalton Hooker and David Lyall, made a major contribution by exploring from Christmas Harbour.
Since its discovery, despite numerous visits, the islands have never been permanently inhabited, particularly by the French, which exposes them to the possibility of dispossession by other countries. Around 1890, England and Australia began to lay claim to the Kerguelens. Consequently, at the suggestion of the Boissière brothers, President Sadi Carnot decided to send the Eure, an aviso french ship under the captaincy of Commander Louis Édouard Paul Lieutard (1842–1902) , to solemnly repossess the Austral Islands on behalf of France. The mission took place in the Kerguelen archipelago from January 1st to 15th 1893, before moving on to Saint Paul Island and Amsterdam Island. On New Year's Day 1893, the Eure arrived at Port-Christmas, where the Francis Allyn, an American seal-hunting schooner under Captain Joseph J. Fuller, happened to be. The French military, reiterating the takeover made 120 years earlier on the same spot, proceeded ashore to raise the colors on the mast and affix a copper plaque engraved "EURE – 1893". Twenty-one cannon shots were fired. Over the following fifteen days, the same operations were repeated at various points around the archipelago. The territory was now ready for the arrival of settlers. Six months later, Henry and René-Émile Bossière obtained an exclusive 50-year concession over the entire French Southern Territories.Returning from an oceanographic expedition to the outskirts of Antarctica, German marine biologist Carl Chun arrived in Port-Christmas aboard the Valdivia in 1898, where he declared himself fascinated by the "romanesque" character of the place.On March 9th, 1908, Raymond Rallier du Baty and his brother Henri anchored their ketch, the J.B. Charcot, before embarking on a methodical exploration of the archipelago. To own a territory, it is essential to be fully acquainted with it and to officially designate its remarkable landmarks, especially with the economic development of Kerguelen in mind. To this effect, the du Baty brothers received moral and financial support from the Société de Géographie to carry out their reconnaissance and mapping work.During the 20th century, Port-Christmas was occasionally used as a site for scientific studies, but its remoteness was an obstacle to continuous monitoring. During the International Geophysical Year in 1957 and 1958, Port-aux-Français was chosen as the site for a permanent magnetic repeat station. In December 1964, the replacement ship, the Gallieni, brought a team to Port-aux-Français to carry out tellurometer measurements and helicopter overflights to produce a general map of the archipelago. This team set up camp in virtually the same location as Ross had chosen in 1840. Two Ferdinand Fillod-type metal cabins were erected in the hope of providing a permanent secondary station. For several years, they were used as shelters for scientific teams during southern summer, but were eventually abandoned and destroyed, and no longer appear on the TAAF or IPEV cabin lists.Given its historic character, the Port-Christmas site is one of several whose artifacts will be inventoried under the 2018–2027 Management Plan from the Réserve naturelle nationale des Terres australes françaises.
== Literature ==
Numerous writers, mainly novelists, have made mention of this place.
In 1838, the American writer Edgar Allan Poe was the first to publish "The Narrative of Arthur Gordon Pym of Nantucket", translated into French in 1858 by Charles Baudelaire under the title Aventures d'Arthur Gordon Pym. In it, he describes the nearly one-month stay on Christmas Harbour in 1827 by the crew of the Jane Guy vessel, who rescued the two main protagonists. Poe accurately describes the natural harbor and the typical arch, sometimes repeating almost verbatim the description given by seal-hunting captain Benjamin Morrell in A Narrative of Four Voyages, published in 1832. In particular, the protagonist Arthur Pym cites Wasp Harbour, a toponym that only Morrell uses to designate his usual anchorage, which resembles Port-Christmas but whose description is too imprecise to be sure.Jules Verne, using Poe's novel as a theme and plot for his own, sets the first three chapters of An Antarctic Mystery (1897) set in the Desolation Islands, where his hero, the American mineralogist Joerling, spends from June to August 1839 in Christmas Harbour, before sailing south on the schooner Halbrane. Without ever having been there, the French novelist gives a precise geographical description and establishes a fictitious cosmopolitan settlement of around twenty inhabitants centered around Fenimore Atkins, the proprietor of the Au Cormoran-Vert inn, living off the seasonal staging of English and American sealers and whalers. The two 19th-century novelists anchored Port-Christmas in the collective imagination as one of the gateways to the Deep South, the Southern Ocean and the Antarctic continent.
Navigator and travel writer Raymond Rallier du Baty docked at Port-Christmas in 1908 to map the archipelago and wrote a literary description in his story On peut aller loin avec des cœurs volontaires.
In 1933, novelist and poet Valery Larbaud published Le gouverneur de Kerguelen (The Governor of Kerguelen), a short story that uses a disciplinary transfer to Port-Noël as a pretext to initiate the game of "ten essential books that one would take to a desert island" and establish a library. He humorously proposes the following rules:"... 'You have had the misfortune to displease those in high places; but in deference to your merits, we have contented ourselves with distancing you by appointing you for one ... three ... five years (that's a maximum) Governor of (sic) Kerguelen, with residence at Port-Noël, the main town of this colony. [...] You will only be able to take with you one... five... ten... twenty books, on condition that they are chosen by you from...'. Here, all suppositions are allowed..."
– Valery Larbaud, 1933.This little game is also the occasion for correspondence between Larbaud and the Dutch literary scholar Edgar du Perron, who proposes and discusses his own choices.Edgar Aubert de la Rüe, who visited the archipelago four times between 1928 and 1953 to carry out various geographical and geological studies, spending many months there in total, mentions Port-Christmas in his brief novel Deux ans aux Îles de la Désolation (1954).In 1993, journalist and writer Jean-Paul Kauffmann, in his story L'Arche des Kerguelen, made Port-Christmas the ultimate goal of a personal quest he undertook in the Kerguelen archipelago a few years after his release from three years' captivity as a hostage in Lebanon. His entire book – which retells the history of the Kerguelen archipelago, its explorers and residents, as well as the details of his own several-week stay – focuses on reaching this mythical place, one of the most isolated in the archipelago and even one of the most inaccessible on Earth, which he never managed to reach despite various attempts by boat, on foot and by helicopter.
French sailor Isabelle Autissier, after a dismasting in 1994 that forced her to make reparations in Port-aux-Français, published a literary biography in 2006, Kerguelen, le voyageur du pays de l'ombre, in which she describes in detail the arrival of the crew of L'Oiseau in the homonymous bay in January 1774, and the onshore takeover led by Messieurs de Rochegude and du Cheyron, based on available historical data (diaries and accounts) and her own experience of the site. She gives the following description:"Beyond the beach, they waded through a grassy swamp and climbed a mound. [...] No trees, no flowers, in the heart of that summer brightened by austerity. The sparse greenery was covered in patches of old snow. The overall atmosphere was sad and cold. Grandiose indeed, but in the manner of a funerary monument when the shine of smooth marble evokes eternity... "
– Isabelle Autissier, 2006.
== Philately ==
At least five TAAF stamps featuring the Port-Christmas location or its immediate surroundings were issued, the first three engraved by Pierre Béquet :
1976: face value of 3.50 francs, commemorating the bicentenary of Cook's arrival in 1776 with a reproduction of the landing scene engraved in 1784 by John Webber;
1979: face value 2.70 francs, illustrating the arrival of explorer Ross at Christmas Harbour in 1840, with a reproduction of Samuel Williams' engraving of the HMS Terror passing in front of the Kerguelen Arch (Arched Rock);
1997: face value of 24 francs, celebrating the bicentenary of Admiral Kerguelen's death, with a depiction of "Le Hâvre [sic] de Noël", one of the French copies of John Webber's engraving;
2001: face value of 3 euros, depicting an actual view of the Kerguelen Arch, engraved from a photograph by Jacques Jubert;
2011: face value of 1.10 euros, depicting the EE Forbin at the Kerguelen arch during its visit to the archipelago from January 17th to 23rd 1978, stamp engraved by Elsa Catelin, issued jointly with Saint-Pierre-et-Miquelon.
== Notes ==
== References ==
== Annex ==
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Islands
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Pseudo-atoll
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A pseudo-atoll, like an atoll, is an island that encircles a lagoon, either partially or completely. A pseudo-atoll differs from an atoll as established by several authorities, such as how it is formed (not by subsidence, nor by coral). It is considered a preferable term to "near-atoll". There is a need for rigorous definition of "pseudo-atoll" before it can be accepted as a general term.
== Definitions ==
Alexander Agassiz gave the term pseudo-atoll to "any ring-shaped reefs not formed as a result of subsidence". while Norman D. Newell and J. Keith Rigby called such reefs non-coral. and "We conclude that almost-atoll should be retained as a descriptive term as defined by Davis and Tayama, and that the use of "near-atoll" as a synonym be abandoned. The value of terms such as "semi-atoll" and "pseudo-atoll" needs close examination and more rigorous definition before being generally accepted." H. Mergner yet states that micro-atolls classify as pseudo-atolls. Professor David R. Stoddart of Berkeley states an "almost-atoll" is an atoll with a central island of left over residue.
== Usage ==
Dr. Edward J. Petuch, author of Cenozoic seas: the view from eastern North America, refers to pseudo-atolls as pseudoatolls with the Everglades Pseudoatoll as an example.
== See also ==
Coral reef
Depression (geology)
== References ==
== Further reading ==
David R. Stottart, Department of Geography, University of California-Berkeley
B. V. Preobrazhenskiĭ, B. V., Contemporary reefs; CRC Press; 1 edition, 1993, ISBN 90-6191-945-2.
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Islands
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San Giacomo in Paludo
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San Giacomo in Paludo is an island north of the Venice Lagoon. It is being repurposed as a cultural center after serving as a monastery, pilgrim refuge, and quarantine island in prior centuries.
== References ==
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Islands
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Unsinkable aircraft carrier
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An unsinkable aircraft carrier is a term sometimes used to refer to a geographically or politically important island that is used to extend the power projection of a military force. Because such an entity is capable of acting as an airbase and is a physical landmass not easily destroyed, it is, in effect, an immobile aircraft carrier that cannot be sunk.
The term unsinkable aircraft carrier first appeared during World War II, to describe the islands and atolls in the Pacific Ocean that became strategically important as potential airstrips for American bombers in their transoceanic war against Japan. To this end, the US military engaged in numerous island hopping operations to oust the occupying Japanese forces from such islands; the US Navy Seabees would often have to subsequently construct airstrips there from scratch—sometimes over entire atolls—quickly, in order to support air operations against Japan.
Midway Atoll has been described as a fourth, unsinkable, American aircraft carrier at the Battle of Midway in 1942 (the Americans had three conventional carriers). It did indeed function this way in the battle, with aircraft from the atoll attacking Japanese carriers and the atoll being attacked in turn.Malta and Iceland were sometimes described as unsinkable aircraft carriers during World War II, making Malta a target of the Axis powers. At the end of the Chinese Civil War, the US military was said to have considered Taiwan an unsinkable aircraft carrier, though this position toward Taiwan changed when the United States and the People's Republic of China normalized relations in the 1970s and the United States annulled the Sino-American Mutual Defense Treaty with Taiwan. However, the United States has de facto maintained the status quo through the Taiwan Relations Act. The US military is also said to have considered the British Isles as unsinkable aircraft carriers during the Cold War. In 1983, Japanese Prime Minister Yasuhiro Nakasone pledged to make Japan an "unsinkable aircraft carrier in the Pacific", assisting the US in defending against the threat of Soviet bombers. US Secretary of State General Alexander Haig described Israel as "the largest American aircraft carrier in the world that cannot be sunk". In arguing against production of the CVA-01 aircraft carriers, the Royal Air Force claimed that Australia could serve adequately in the same role, using false maps that placed Singapore 400 miles (640 km) closer to Australia.
The island of Cyprus is also often described as an unsinkable aircraft carrier, in relation to the military presence of the United Kingdom there.
During the Second World War, the United Kingdom gave some serious thought to building virtually unsinkable aircraft carriers from ice reinforced with sawdust (Project Habakkuk). A model was made, and serious consideration was given to the project, with a design displacing 2.2 million tons and accommodating 150 twin-engined bombers on the drawing board, but it was never produced.
== See also ==
Diego Garcia
Military on Gotland
Mobile offshore base
Strategic geography
Tinian in World War II
Territorial disputes in the South China Sea
== References ==
== Further reading ==
Abraham, Itty (2015). "India's Unsinkable Aircraft Carrier". Economic and Political Weekly. 50 (39): 10–13. ISSN 0012-9976. JSTOR 24482452.
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Islands
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Category:Islands by body of water
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This category includes articles on islands and islets, organized by their physical location.
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Category:Islands by city
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Category:Islands by continent
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Islands
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Category:Islands by country
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This category includes articles on islands, organized by their sovereign country which may differ from their physical location.
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Islands
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Category:Islands by dependent territory
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Islands
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Category:Islands by type
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Islands
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Category:Lists of islands
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These are lists of islands.
See list of islands for an overview.
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Islands
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Category:Categories by island
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Islands
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Category:Archipelagoes
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Island arcs and other archipelagoes.
Archipelago articles are placed in the archipelago category of their ocean and in the island category of their country.
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Category:Car-free islands
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Islands
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Category:Island countries
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This includes countries that consist of an island, an archipelago, or part of an island.
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Category:Disputed islands
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These are islands or islets that have been disputed for sovereignty. Usually the surrounding waters are considered in dispute as well.
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Islands
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Category:Islands in fiction
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Fiction set on islands.
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Islands
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Category:Former islands
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Islands
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Category:Island Games
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Islands
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Category:Insular ecology
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This category is for the ecology of actual islands, as well as the ecological effects of insular isolation (e.g. may include peninsulas, etc.).
== See also ==
Life zone
Sky island
Oasis
Endemism
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Islands
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Category:International islands
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Islands in which the territory is divided between two sovereign states or (more rarely) held in common by two sovereign states. For islands that are the subject of disputed sovereignty, see Category:Disputed islands.
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Category:Uninhabited islands
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This category is for islands that are uninhabited.
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Category:Wikipedia categories named after islands
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National_parks
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National park
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A national park is a natural park in use for conservation purposes, created and protected by national governments. Often it is a reserve of natural, semi-natural, or developed land that a government declares or owns. Although individual countries designate their own national parks differently, there is a common idea: the conservation of 'wild nature' for posterity and as a symbol of national pride. National parks are almost always open to visitors.The United States established the first "public park or pleasuring-ground for the benefit and enjoyment of the people", Yellowstone National Park, in 1872. Although Yellowstone was not officially termed a "national park" in its establishing law, it was always termed such in practice and is widely held to be the first and oldest national park in the world. However, the Tobago Main Ridge Forest Reserve (in what is now Trinidad and Tobago; established in 1776), and the area surrounding Bogd Khan Uul Mountain (Mongolia, 1778), which were restricted from cultivation in order to protect surrounding farmland, are seen as the oldest legally protected areas. Parks Canada, established on May 19, 1911, became the world's first national park service.An international organization, the International Union for Conservation of Nature (IUCN), and its World Commission on Protected Areas (WCPA), has defined "National Park" as its Category II type of protected areas. According to the IUCN, 6,555 national parks worldwide met its criteria in 2006. IUCN is still discussing the parameters of defining a national park.
== Definitions ==
In 1969, the IUCN declared a national park to be a relatively large area with the following defining characteristics:
One or several ecosystems not materially altered by human exploitation and occupation, where plant and animal species, geomorphological sites and habitats are of special scientific, educational, and recreational interest or which contain a natural landscape of great beauty;
Highest competent authority of the country has taken steps to prevent or eliminate exploitation or occupation as soon as possible in the whole area and to effectively enforce the respect of ecological, geomorphological, or aesthetic features which have led to its establishment; and
Visitors are allowed to enter, under special conditions, for inspirational, educative, cultural, and recreative purposes.In 1971, these criteria were further expanded upon leading to more clear and defined benchmarks to evaluate a national park. These include:
Minimum size of 1,000 hectares within zones in which protection of nature takes precedence
Statutory legal protection
Budget and staff sufficient to provide sufficient effective protection
Prohibition of exploitation of natural resources (including the development of dams) qualified by such activities as sport, hunting, fishing, the need for management, facilities, etc.While the term national park is now defined by the IUCN, many protected areas in many countries are called national park even when they correspond to other categories of the IUCN Protected Area Management Definition, for example:
Swiss National Park, Switzerland: IUCN Ia – Strict Nature Reserve
Everglades National Park, United States: IUCN Ib – Wilderness Area
Koli National Park, Finland: IUCN II – Surface Area
Victoria Falls National Park, Zimbabwe: IUCN III – National Monument
Vitosha National Park, Bulgaria: IUCN IV – Habitat Management Area
New Forest National Park, United Kingdom: IUCN V – Protected Landscape
Etniko Ygrotopiko Parko Delta Evrou, Greece: IUCN VI – Managed Resource Protected AreaWhile national parks are generally understood to be administered by national governments (hence the name), in Australia, with the exception of six national parks, national parks are run by state governments and predate the Federation of Australia; similarly, national parks in the Netherlands are administered by the provinces. In Canada, there are both national parks operated by the federal government and provincial or territorial parks operated by the provincial and territorial governments, although nearly all are still national parks by the IUCN definition.In many countries, including Indonesia, the Netherlands, and the United Kingdom, national parks do not adhere to the IUCN definition, while some areas which adhere to the IUCN definition are not designated as national parks.
=== Terminology ===
As many countries do not adhere to the IUCN definition, the term "national park" may be used loosely. In the United Kingdom, and in some other countries such as Taiwan, a "national park" simply describes a general area that is relatively undeveloped, scenic, and attracts tourists, with some form of planning restrictions to ensure it maintains those characteristics. There may be substantial human settlements within the bounds of a national park.
Conversely, parks that meet the criteria may be not be referred to as "national parks". Terms like "preserve" or "reserve" may be used instead.
== History ==
=== Early references ===
Starting in 1735 the Naples government undertook laws in order to protect Natural areas, which could be used as a game reserve by the royal family; Procida was the first protected site; the difference between the many previous royal hunting preserves and this one, which is considered to be closer to a Park rather than a hunting preserve, is that Neapolitan government already considered the division into the present-day wilderness areas and non-strict nature reserves.In 1810, the English poet William Wordsworth described the Lake District as a "sort of national property, in which every man has a right and interest who has an eye to perceive and a heart to enjoy." The painter George Catlin, in his travels through the American West, wrote during the 1830s that Native Americans in the United States might be preserved "(by some great protecting policy of government) ... in a magnificent park ... A nation's Park, containing man and beast, in all the wild and freshness of their nature's beauty!"
=== First efforts: Hot Springs, Arkansas and Yosemite Valley ===
The first effort by the U.S. Federal government to set aside such protected lands was on 20 April 1832, when President Andrew Jackson signed legislation that the 22nd United States Congress had enacted to set aside four sections of land around what is now Hot Springs, Arkansas, to protect the natural, thermal springs and adjoining mountainsides for the future disposal of the U.S. government. It was known as Hot Springs Reservation, but no legal authority was established. Federal control of the area was not clearly established until 1877. The work of important leaders who fought for animal and land conservation were essential in the development of legal action. Some of these leaders include President Abraham Lincoln, Laurance Rockefeller, President Theodore Roosevelt, John Muir, and First Lady, Lady Bird Johnson to name a few.John Muir is today referred to as the "Father of the National Parks" due to his work in Yosemite. He published two influential articles in The Century Magazine, which formed the base for the subsequent legislation.President Abraham Lincoln signed an Act of Congress on 1 July 1864, ceding the Yosemite Valley and the Mariposa Grove of giant sequoias (later becoming Yosemite National Park) to the state of California. According to this bill, private ownership of the land in this area was no longer possible. The state of California was designated to manage the park for "public use, resort, and recreation". Leases were permitted for up to ten years and the proceeds were to be used for conservation and improvement. A public discussion followed this first legislation of its kind and there was a heated debate over whether the government had the right to create parks. The perceived mismanagement of Yosemite by the Californian state was the reason why Yellowstone was put under national control at its establishment six years later.
=== First national park: Yellowstone ===
In 1872, Yellowstone National Park was established as the United States' first national park, being also the world's first national park. In some European and Asian countries, however, national protection and nature reserves already existed - though typically as game reserves and recreational grounds set aside for royalty, such as a part of the Forest of Fontainebleau (France, 1861).Yellowstone was part of a federally governed territory. With no state government that could assume stewardship of the land, the federal government took on direct responsibility for the park, the official first national park of the United States. The combined effort and interest of conservationists, politicians and the Northern Pacific Railroad ensured the passage of enabling legislation by the United States Congress to create Yellowstone National Park. Theodore Roosevelt and his group of conservationists, the Boone and Crockett Club, were active campaigners and were highly influential in convincing fellow Republicans and big business to back the bill. Yellowstone National Park soon played a pivotal role in the conservation of these national treasures, as it was suffering at the hands of poachers and others who stood at the ready to pillage what they could from the area. Theodore Roosevelt and his newly formed Boone and Crockett Club successfully took the lead in protecting Yellowstone National Park from this plight, resulting in laws designed to conserve the natural resources in Yellowstone and other parks under the Government's purview.American Pulitzer Prize-winning author Wallace Stegner wrote: "National parks are the best idea we ever had. Absolutely American, absolutely democratic, they reflect us at our best rather than our worst."
=== International growth of national parks ===
The first area to use "national park" in its creation legislation was the U.S.'s Mackinac National Park, in 1875. (The area was later transferred to the state's authority in 1895, thus losing its official "national park" status.)
Following the idea established in Yellowstone and Mackinac, there soon followed parks in other nations. In Australia, what is now Royal National Park was established just south of Sydney, Colony of New South Wales, on 26 April 1879, becoming the world's second official national park Since Mackinac lost its national park status, the Royal National Park is, by some considerations, the second oldest national park now in existence.
Banff National Park became Canada's first national park in 1885. New Zealand established Tongariro National Park in 1887.
In Europe, the first national parks were a set of nine parks in Sweden in 1909, followed by the Swiss National Park in 1914. Africa's first national park was established in 1925 when Albert I of Belgium designated an area of what is now Democratic Republic of Congo centred on the Virunga Mountains as the Albert National Park (since renamed Virunga National Park).
In 1895, the Groenkloof Nature Reserve was established as the first game sanctuary in Africa. In 1926, the government of South Africa designated Kruger National Park as the nation's first national park, although it was an expansion of the earlier Sabie Game Reserve established in 1898 by President Paul Kruger of the old South African Republic, after whom the park was named.
Argentina became the third country in the Americas to create a national park system, with the creation of the Nahuel Huapi National Park in 1934, through the initiative of Francisco Moreno.After World War II, national parks were founded all over the world. The United Kingdom designated its first national park, Peak District National Park, in 1951. This followed perhaps 70 years of pressure for greater public access to the landscape. By the end of the decade a further nine national parks had been designated in the UK. Europe has some 359 national parks as of 2010. The Vanoise National Park in the Alps was the first French national park, created in 1963 after public mobilization against a touristic project.
In 1971, Lahemaa National Park in Estonia was the first area to be designated a national park in the former Soviet Union.
In 1973, Mount Kilimanjaro was classified as a National Park and was opened to public access in 1977.In 1989, the Qomolangma National Nature Preserve (QNNP) was created to protect 3.381 million hectares on the north slope of Mount Everest in the Tibet Autonomous Region of China. This national park is the first major global park to have no separate warden and protection staff—all of its management being done through existing local authorities, allowing a lower cost basis and a larger geographical coverage (in 1989 when created, it was the largest protected area in Asia). It includes four of the six tallest mountains in the world: Everest, Lhotse, Makalu, and Cho Oyu. The QNNP is contiguous to four Nepali national parks, creating a transborder conservation area equal in size to Switzerland.In 1993, the Blue and John Crow Mountains National Park was established in Jamaica to conserve and protect 41,198 hectares, including tropical montane rainforest and adjacent buffer areas. The site includes Jamaica's tallest peak (Blue Mountain Peak), hiking trails and a visitor center. The Park was also designated a UNESCO World Heritage Site in 2015.
=== National parks services ===
The world's first national park service was established May 19, 1911, in Canada. The Dominion Forest Reserves and Parks Act placed the dominion parks under the administration of the Dominion Park Branch (now Parks Canada), within the Department of the Interior. The branch was established to "protect sites of natural wonder" to provide a recreational experience, centred on the idea of the natural world providing rest and spiritual renewal from the urban setting. Canada now has the largest protected area in the world with 450,000 km2 of national park space.Even with the creation of Yellowstone, Yosemite, and nearly 37 other national parks and monuments, another 44 years passed before an agency was created in the United States to administer these units in a comprehensive way – the U.S. National Park Service (NPS). The 64th United States Congress passed the National Park Service Organic Act, which President Woodrow Wilson signed into law on 25 August 1916. Of the 425 sites managed by the National Park Service of the United States, only 63 carry the designation of National Park.
== Notable parks ==
The largest national park in the world meeting the IUCN definition is the Northeast Greenland National Park, which was established in 1974 and is 972,000 km2 (375,000 sq mi) in area.The smallest official national park in the world is Isles des Madeleines National Park. Its area of just 0.45 square kilometres (0.17 sq mi) was established as a national park in 1976.
== Economic ramifications ==
Countries with a large ecotourism industry, such as Costa Rica, often experience a huge economic effect on park management as well as the economy of the country as a whole.
=== Tourism ===
Tourism to national parks has increased considerably over time. In Costa Rica for example, a megadiverse country, tourism to parks has increased by 400% from 1985 to 1999. The term national park is perceived as a brand name that is associated with nature-based tourism and it symbolizes a "high quality natural environment with a well-designed tourist infrastructure".
=== Staff ===
The duties of a park ranger are to supervise, manage, and/or perform work in the conservation and use of park resources. This involves functions such as park conservation; natural, historical, and cultural resource management; and the development and operation of interpretive and recreational programs for the benefit of the visiting public. Park rangers also have fire fighting responsibilities and execute search and rescue missions. Activities also include heritage interpretation to disseminate information to visitors of general, historical, or scientific information. Management of resources such as wildlife, lake shores, seashores, forests, historic buildings, battlefields, archaeological properties, and recreation areas are also part of the job of a park ranger. Since the establishment of the National Park Service in the US in 1916, the role of the park ranger has shifted from merely being a custodian of natural resources to include several activities that are associated with law enforcement. They control traffic, manage permits for various uses, and investigate violations, complaints, trespass/encroachment, and accidents.
== Concerns ==
National parks in former European colonies have come under criticism for allegedly perpetuating colonialism. National parks were created by individuals who felt that pristine, natural sections of nature should be set aside and preserved from urban development. In America, this movement came about during the American Frontier and were meant to be monuments to America's true history. Yet the lands that were to be set aside and protected were already being inhabited by native communities, who were removed and set aside to create pristine sites for public consumption. Critics claim that the removal of people from national parks enhanced the belief that nature can only be protected when humans do not exist within it, and that this leads to perpetuating the dichotomy between nature and humans (also known as the nature–culture divide). They see creation of national parks as a form of eco-land grabbing. Others claim that travelling to national parks to appreciate nature there leads people to ignore the nature that exists around them every day. Some argue that tourism can actually negatively impact the areas that are being visited.
== See also ==
== References ==
=== Citations ===
=== Sources ===
Eagles, Paul F. J; McCool, Stephen F. (2002). Tourism in National Parks and Protected Areas: Planning and Management. CABI. ISBN 0851997597. 320 pages.
Sellars, Richard West (2009). Preserving Nature in the National Parks: A History. Yale University Press. ISBN 978-0300154146. 404 pages.
Sheail, John (2010) Nature's Spectacle - The World's First National Parks and Protected Places Earthscan, London, Washington. ISBN 978-1-84971-129-6
== External links ==
"Areas of Biodiversity Importance: National Parks". Biodiversity A-Z. Archived from the original on 16 May 2011. Retrieved 21 April 2011.
"Europe's protected areas". EUROPARC Federation.
"FAQs". U.S. National Park Service.
Macomber, Drew (10 September 2018). "Map of All The World's National Parks". Travel Is Free.
"Man and the Biosphere Programme (Biosphere Reserves)". UNESCO. 7 January 2019.
"National parks, landscape parks and protected areas in the world". nighthee.com. Archived from the original on 5 September 2015. Retrieved 11 August 2015.
"National Parks Worldwide". amu.edu.pl. Archived from the original on 19 January 2008. Retrieved 3 January 2008.
"World Database of Protected Areas". Protected Planet.
"Digital Observatory for Protected Areas (DOPA)". by the Joint Research Centre of the European Commission.
"World Heritage Sites". UNESCO.
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National_parks
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Lake Mburo- Nakivali Wetland System
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Lake Mburo-Nakivali Wetland System is a wetland located in Mbarara district, 60 km from Mbarara town in western Uganda, East Africa, bordering Tanzania and Rwanda. The system encompasses five lakes lying in the National park including Mburo being the largest, Kigambira, Mutukula, Kazuma and Bwara in the west-east location.It is a habitat for birds such as Palearctic as well as fish species including impala and cichlid. It is a source of water for domestic use, wildlife, and livestock. It is also a source of food including fish, provides pastures for herds, as well as materials for making crafts, baskets, and thatching.
== Setting and Structure ==
Lake Mburo-Nakivali Wetland System is situated at Latitude 00°40′ south and Longitude 030°57′ East.
== See Also ==
Lake Nabugabo Wetland SystemLake George Uganda
== References ==
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National_parks
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Our Great National Parks
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Our Great National Parks is a five-part Netflix documentary series about some of the world's national parks and their wildlife. It is presented by former president of the United States Barack Obama and was released on April 13, 2022.
== Cast ==
Barack Obama, narrator
== Critical assessment ==
The documentary received generally positive reviews upon its release. A reviewer writing for the Hollywood Reporter described Obama's skills as a narrator: "He explains the synergistic ways in which governmentally reserved natural spaces can have non-antagonistic relationships with nearby human populations. He contributes wry humor to the scripts, with their slightly superficial, overly anthropomorphic explanations for animal behavior. And, more than that, his trademark deliberate cadences and oft-emulated calculated pauses are a perfect delivery mechanism for letting lovely nature photography breathe", adding that it "doesn’t push too hard to be educational [but]....Just because Our Great National Parks isn’t always revelatory definitely doesn’t mean, though, that it isn’t generally attractive and occasionally breathtaking."A reviewer writing for the Houston Press said that the series is "the single most calming thing on television" and went on to say that "What truly sets Our Great National Parks apart, though, is the message woven into the episodes. Pragmatically, Obama tells us how various parts of humanity have made preserving the wild world a priority."The review in the San Diego Union Tribune observed that the series is "devoted to the eye-popping, heart-stopping, consciousness-raising wonders of the world’s most astounding national parks."A less favorable review in The Daily Telegraph described the series as "dazzlingly gorgeous yet a long way short of groundbreaking" and compared Obama's role negatively to David Attenborough, concluding "where David Attenborough enthusiastically brings to life the tooth and claw rhapsody of the natural world, Obama sounds stilted, even bored."
== Episodes ==
== Release ==
=== Accolades ===
== References ==
== External links ==
Our Great National Parks at IMDb
Our Great National Parks on Netflix
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