Several islands in close proximity can form an island group . Together with the waters in between, they are also referred to as the archipelago . Of the 193 sovereign states in the world recognized by the United Nations , 47, or around a quarter, are island states .
Definition and demarcation issues
Island size and habitability
The actual dimensions of a completely washed land mass are irrelevant for the definition of the island. Even small rock formations, such as the archipelago off the Scandinavian Baltic coasts or Holme in the North Atlantic, are usually considered islands. Even the smallest motus of atolls in the southern oceans are therefore islands.
The outdated term " island " mostly refers to a small island and does not depend on a specific island shape.
Whether a land mass is inhabited by people, was previously inhabited or is at least habitable today, is also irrelevant for the classification of a land mass as an island (see uninhabited island ).
Delimitation to the peninsula
Artificial structures (canals, bridges, road embankments) that separate an island from a land mass or connect it to it are irrelevant. If a land mass is only enclosed by water on three sides or if there is a natural, not constantly flooded connection to a larger land mass, one speaks of a peninsula . A headland is a special form of the peninsula, as its connection to the mainland is no narrower than its greatest width.
Delimitation to the atoll
An atoll is not an island in the strictest sense, but an archipelago consisting of small sand or coral islands ( motu ) that surrounds a lagoon . A rare exception are the upscale atolls , where the motu were raised by tectonic processes and the central lagoon silted up afterwards and is often covered with vegetation. Other special cases are atolls that only have a single island, e.g. B. Ceva-i-Ra , some of the Rowley Shoals or the Indispensable Reefs , as well as those that have formed a closed ring of land around the central lagoon, e.g. B. North Keeling .
Differentiation from other structures
- Natural structures that are not permanently connected to the bottom of the water, e.g. For example : icebergs , ice floes and so-called " floating islands " are not considered islands, even if such an object sits firmly on the ground for a long time (see Pobeda (iceberg) ).
- Although permanently connected to the underground, an ice dome is not an island either. Sometimes the difference to an ice-covered "real" island can only be determined with echo sounder measurements .
- Of open water surrounded reed beds , z. B. the "Schoppen" of the Neusiedler See , are also not islands.
- Man-made sand deposits in the sea or in inland waterways can form artificial islands .
- Structures in a body of water, such as drilling platforms , lighthouses , wind turbines , pile dwellings and comparable objects firmly connected to the subsurface, are not islands, however, as there is no defining feature of land mass .
- Boulders and other large stones that are completely surrounded by water but are not firmly connected to the ground due to their history of origin are also not considered islands, for example the Schwanenstein , Buskam or the Georgenstein .
- Gravel banks are not islands, even if they are commonly referred to as "gravel islands".
- The same applies to rocky shallows that sometimes protrude above the water level, such as B. the Krausaue in the Upper Rhine .
- A special form are the tidal islands , which, depending on the tide level , are viewed as an island or an elevation. Similar to this are sandbanks , which are considered to be high sand either permanently or temporarily as islands.
There are two types of islands in terms of location:
- Oceanic islands, which mostly rise from the open ocean either as part of mid- ocean ridges or as the result of hotspot volcanism away from the continents, therefore mostly volcanic islands or atolls (coral reef islands with volcanic bases)
- Continental islands that rest on the shelf or are in a shelf sea in relative proximity to a large continental land mass.
Another distinction depends on the type of water in which the island is located:
- Sea islands: all islands that are surrounded by sea regions, regardless of whether it is a shallow sea (shelf sea) or the deep, open ocean. Examples: Heligoland , Madeira , Cyprus , Hawaii , Cuba , Hainan , etc.
- Inland islands
Island flora and fauna
Many islands have produced their own fauna and flora, which are more or less different in composition from neighboring islands or the continent. A distinction has to be made between continental and oceanic islands. While continental islands were isolated from a continent by plate tectonic or eustatic processes, oceanic islands were created directly within an ocean basin, usually through volcanism, and were never connected to a continent.
The flora and fauna of the former supercontinent Pangea is to a certain extent still represented today in one or the other flora and fauna of continental islands, but completely new animal and plant communities with a generally high number of endemites have emerged in the millions of years of separation . Islands without genetic exchange with their populations are therefore nature's laboratories . The wildlife of New Zealand, for example, is unique: 85 percent of the animals (not introduced by humans) are only found here and nowhere else in the world. Although New Zealand is relatively close to the Australian continent, the living world of the archipelago has developed completely differently since the separation in the Cretaceous .
The smaller, younger and more isolated an oceanic island, the fewer species the flora and fauna tend to be. This can be seen very clearly with the Pacific islands. The plants in the South Pacific are of Australasian origin and spread from west to east. This led to the islands' biodiversity decreasing towards the east. Tahiti, for example, has a much higher number of species than the Pitcairn Islands further east and Easter Island.
Animal species on islands are often significantly smaller or larger than their closest relatives on the continents. Island dwelling is possibly an adaptation to permanent food shortages due to overpopulation in a spatially restricted environment. For example, on the bare Wrangel Island in the Arctic Ocean, which belongs to Russia , remains of a dwarf woolly woolly mammoth have been found that were only about 1.8 m tall when fully grown (mammoths on the Siberian mainland reached a size of 3.0 to 3.5 m) .
Island gigantism is essentially the result of the lack of food competitors and predators when there is a plentiful supply of food, so that the individuals of a species can grow larger and larger from generation to generation without being disturbed. The island of New Zealand once housed, until its extinction by the Māori , the moas , the largest ratites on earth, which could be over 3 m tall. Other examples of island gigantism are the Komodo dragon , a scaled reptile over two meters long that lives on the Lesser Sunda Islands , and the giant tortoises in the Seychelles and the Galapagos Islands .
If birds, which normally do not fly long distances, end up on relatively remote islands without competition for food or predators, they often lose their ability to fly within a few generations. A prominent example of flightless birds on islands is the dodo , which lived on Mauritius until the second half of the 17th century . Adult individuals of the dodo weighed over 20 kilograms. Introduced rats, feral domestic animals and the intensive hunt for the "clumsy" birds eventually led to the extinction of the species. Further examples are the kiwifruit in New Zealand and the colobus cormorant in the Galapagos. But islands, especially the less remote ones, are also generally important refuge areas for many bird species. In order to be able to pursue their breeding business undisturbed, the more persistent fliers cover thousands of kilometers below them.
On remote islands you can often find untouched nature. In the Arctic and the Pacific there are still uninhabited islands off all traffic routes that are only entered by humans once or twice a decade. On the other hand, humans have withdrawn from islands that were once inhabited and declared them nature reserves .
The island as a settlement area
Islands were settled very early in human history, probably only by a few pioneers at first. A group of 25 people should be the minimum - from a biological, social and psychological point of view - to permanently colonize an island. According to current research, Crete is probably the earliest permanently inhabited island. In the early summer of 2009, American archaeologists found stone tools on the western slopes of the Preveli Gorge , presumably by Neanderthals , dating back more than 130,000 years (possibly even up to 700,000 years). In Cagayan Valley on the island of Luzon have been excavated human bones and tools that are 67,000 years old.
Islands offered a certain security against attacks, which was probably one of the main reasons to settle on islands. A campaign of conquest over the sea turns out to be difficult and risky, one can definitely speak of a "fortress island". Philip II of Spain had to find out about this in 1588 , when the entire Spanish Armada was lost in an attempt to invade England .
Security creates continuity in the development of a culture and therefore it is not surprising that some advanced cultures were able to emerge on islands. Cult sites on the island of Malta date from the Neolithic and prove a solid, high-quality culture as early as the 3rd millennium BC. Chr.
Some islands were home to important peoples with complex advanced civilizations. Mainly to be mentioned here are: Crete , the Japanese islands , the British islands , the Indonesian islands Java and Bali , the island Sri Lanka , but also some of the oceanic islands, for example Easter Island . The emergence of a high culture does not seem to be dependent on the size of the island; The tiny and resource-poor Easter Island produced a culture with a highly sophisticated art and architecture, but the peoples of Greenland and New Guinea , the two largest islands on earth, remained largely at the level of hunters and gatherers .
Island peoples have always been closely connected to the surrounding sea. This led to the emergence of rich and powerful seafaring nations engaged in trade, for example the Minoan culture on Crete or the city-state of Venice, which is distributed over the islands of the lagoon . In the Pacific there was a trade network that had existed for centuries, worked over distances of several thousand kilometers and included numerous Polynesian islands, from Hawaii to the Austral Islands , from New Zealand to the Marquesas .
Today islands are among the most densely populated regions on earth, and they are home to some of the largest cities: the metropolitan regions around Tokyo on the island of Honshū and Jakarta on Java are the largest on earth. The metropolitan areas around New York City and Mexico City , which are also among the largest in the world, emerged on smaller islands.
Cultural area island
Islands have always inspired artists and have often been the subject of important works of all art directions, for example in the literature Treasure Island by Robert Louis Stevenson , in Shakespeare's theater The Tempest , in the fine arts the paintings by Paul Gauguin with motifs from Tahiti or The Isle of the Dead by Arnold Böcklin , in the music of the chanson La Cathédrale by Jacques Brel , who was inspired to do so by the silhouette of the island of Ua Pou , and in the film the numerous, mainly set in the South Seas, such as the silent film Tabu by Friedrich Wilhelm Murnau , 1931 shot on Bora Bora , or Cast Away by Robert Zemeckis with Tom Hanks in the lead role.
But the island peoples have also found diverse and demanding, independent artistic forms of expression: the moai and the wood carving art of Easter Island , the kabuki theater in Japan, Icelandic literature , the hula dance of Hawaii , the scrimshaws of the whalers of Nantucket or the artistic book illustrations from the time of the Irish high kings , for example the " Book of Kells ". It is likely that many works of art have been lost over the centuries, whether they were fleeting works made from non-permanent materials or no records exist (many of the island peoples knew no writing). For example, the music and dance of the island Caribs have completely disappeared because the Spanish conquerors did not bother to record them. But although the art of the indigenous people has not been passed down, the Antilles have found new forms of artistic expression from the merging of European, African and American elements. One example is that of the island of Jamaica native Reggae 20th century. We only know about the demanding tattoo patterns of the Marquesas through the research of the doctor and ethnologist Karl von den Steinen , who visited the archipelago at the beginning of the 20th century, when the missionaries had already suppressed the practice of tattooing. Today's tattooists in the Marquesas have to resort to von den Steinens books for their motifs.
On islands, researchers received essential suggestions for groundbreaking theories that shape our view of the world today. During his visit to the Galapagos Islands , Charles Darwin developed his theory of evolution and in the Malay Archipelago , Alfred Russel Wallace developed the basis for his theory of the Wallace Line , the biogeographical boundary between the Asian and Australian fauna.
Other functions of islands
In the early Hanseatic era , the island of Gotland served as a stopover for the Hanseatic trade in Russia, where merchants also spent the winter. Gotland lost this function, however, in the later Hanseatic era due to a significant acceleration in travel times, which ultimately made stopovers less necessary. For the early explorers in the Pacific, individual islands and groups of islands were important supply stations for food, especially for fresh water. At the time of transatlantic trade with sailing ships, fresh food or other goods could be added to the Canary Islands and Madeira .
Due to their location isolated from the mainland, in particular very remote or very small islands of a maximum size of a few square kilometers can easily be sealed off from the outside world. This can fulfill various functions. The island of Riems in Mecklenburg-Western Pomerania is used as a virological research site. The two populated islands of the so-called pea islands north of the Danish island of Bornholm were initially set up as a military observation post (especially towards Sweden) and as a naval base, but from the 18th century to 1855 they also served as a place of exile and prison (under for Jacob Jacobsen Dampe ). Another historical example of an island that was initially used for military purposes and then as a prison is Alcatraz on the US west coast near San Francisco, where prisoners who were considered to be particularly dangerous were penalized between the 1930s and 1960s. The French general and emperor Napoleon Bonaparte was initially exiled to the Mediterranean island of Elba and later to the offshore island of St. Helena in the South Atlantic.
Islands far off the mainland coast are still often used today as weather observation stations. Trials of car-free traffic or the restriction of motorized traffic to sustainably produced operating materials are more likely to meet with acceptance on islands and are also easier to implement ( Hiddensee example ).
Islands in mythology
In peoples' stories, islands were often portrayed as beyond the horizon, inaccessible gardens of Eden or lost paradises . Examples of this are the mythical Avalon from the Arthurian legends or the island of Kythera, Aphrodite's legendary island of love , which is described in detail in the Hypnerotomachia Poliphili . Belief in the mythical islands was so strong that some of them were even recorded in early maps, for example the Saint Brendan's Islands , the island of Antilia in the Atlantic Ocean or the island kingdom of Atlantis .
The myth of the "island paradise" lasted into modern times and was furthered by the expeditions of the 18th and 19th centuries. Louis Antoine de Bougainville's romanticized travelogue “Voyage autour du monde” from 1771 and Georg Forster's 1777 travel description “A Voyage Round The World” about James Cook's Pacific voyage seemed to confirm Jean-Jacques Rousseau's image of the “ noble savage ” that the Europeans believed to have found on the islands of the South Seas . "An Arcadia whose kings we will be," wrote the botanist Joseph Banks , who accompanied James Cook on his first voyage and circumnavigation (1768–1771), of the island of Tahiti.
But islands were also considered the home of ghastly monsters. The Minotaur , a hybrid of man and bull , allegedly lived in the labyrinth on Crete . The French researcher and writer André Thevet reports on the "Island of Demons" in the far north of the Atlantic, still north of Newfoundland , where the griffin and other beasts and evil spirits were supposed to be up to mischief.
Belief in mysterious, dangerous and threatening islands extends into modern times. The Flannan Isles , a group of eight uninhabited, small islands in north-west Scotland, have always been considered haunted places of evil by local fishermen. People shied away from entering them, and when it was inevitable, appeasement rites were performed and sacrificial gifts were placed on the beach. At the end of the 19th century, a lighthouse was built on the main island of Eilean Mòr. A permanent crew of three men was supposed to maintain the signal light and keep it in operation. When the supply ship Hesperus reached the island on December 26, 1900, there was no sign of life from the three lighthouse keepers. They were gone without leaving the slightest trace. The mysterious incident concerns mystics to this day. Paranormal events as well as the abduction by aliens must serve as an explanation.
Largest, tallest and most populous islands on earth
Below are the 10 largest islands on earth , all of which are located in seas:
|island||location||Area in km²|
|2.||New Guinea||Western pacific||786,000|
|5.||Baffin Island||North Atlantic||507.451|
|8th.||Great Britain||North Atlantic||229,883|
|9.||Victoria Island||Arctic Ocean||217.291|
|10.||Ellesmere Island||Arctic Ocean||196.236|
The largest island in an inland lake is Manitoulin , in Ontario , Canada . The 2,766 km² island is located in Lake Huron , one of the Great Lakes in North America, with freshwater lakes throughout . Manitoulin, for its part, has numerous lakes, in which several islands are located (the largest of which are Treasure Island in Mindemoya Lake and Kakawaie Island in Lake Kagawong).
- Inselkette , Inselbogen
- Main island , secondary island
- Double island
- Hallig , Cay
- Dune island , island core
- Phantom Island
- List of European islands by area
- Henry William Menard: Islands: Geology and History of Land in the Sea. Spectrum of Science, Heidelberg 1987, ISBN 978-3-922508-85-4 .
- Paul Rainbird: The archeology of islands. Cambridge Univ. Press, New York 2007, ISBN 978-0-521-85374-3
- Brooks, Lillie: Islands of the World: Names of Over 5,000 Islands and Island Groups . Bakersfield? 1960.
- Anthony Julian Huxley: Standard Encyclopedia of the World's Oceans and Islands . Putnam Pub Group, 1962.
- Rosemary Gillespie and David A. Clague (Eds.): Encyclopedia of Islands . University of California Press, 2009, ISBN 0-520-25649-2 ( excerpt from Google Books )
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- Jon Richards: Islands around the world. PowerKids Press, New York 2009, ISBN 978-1-4358-2872-8 (excerpt in Google Books )
- NC Matalas, Bernardo F. Grossling: Habitat and Environment of Islands - Primary and Supplemental Island Sets. US Geological Survey Professional Paper 1590 ( online )
For literary and cinematic reception
- Anne-Marie Fröhlich (Ed.): Islands in world literature. Manesse Verlag, Zurich 1989, ISBN 3-7175-1762-7
- Hans Richard Brittnacher (Ed.): Islands . Edition Text + Criticism, Munich 2017, ISBN 978-3-86916-520-2 .
- Duden - German Universal Dictionary. 5th edition. Dudenverlag, Mannheim 2003, (keyword “peninsula”).
- Definition of the peninsula. Insel-Lexikon (insel-lexikon.com)
- Ordinance of the Munich District Office regulating access to the gravel islands in the Isar between river km 164.6 and river km 162.5 in the Isartal landscape protection area. ( Memento from November 20, 2011 in the Internet Archive ) District Office Munich, 2001
- Steven Roger Fischer: Islands - From Atlantis to Zanzibar . Reaction Books, London 2012, ISBN 978-1-78023-032-0 .
- J. Bristol Foster: The Evolution of Mammals on Islands . In: Nature. Vol. 202, 1964, pp. 234-235.
- Adrian Lister, Paul Bahn: Mammuts - The Giants of the Ice Age . Thorbecke, Sigmaringen 1997, ISBN 3-7995-9050-1 , pp. 34-35.
- John Noble Wilford: On Crete, New Evidence of Very Ancient Mariners. The New York Times (nytimes.com) February 15, 2010.
- Armand Salvador Mijares et al .: New evidence for a 67,000-year-old human presence at Callao Cave, Luzon, Philippines. In: Journal of Human Evolution. Volume 59 (1) from July 2010, pp. 123-132.
- Marshall I. Weisler: Long-distance interaction in prehistoric Polynesia: three case studies. University of California, Berkeley 1993 (PhD thesis).
- Karl von den Steinen: The Marquesans and their art - studies on the development of primitive South Sea ornaments based on own travel results and the material of the museums. 3 volumes, Reimer, Berlin 1925–1928.
- Donald S. Johnson: Mirage of the Seas - The vanished islands of the Atlantic . Diana Verlag, Munich-Zurich 1999, ISBN 3-8284-5019-9 , pp. 85-86.
- Flannan Isles. Page with details of the disappearance of the three lighthouse keepers, website of the Northern Lighthouse Board in Edinburgh
- Topographic Map of Canada 1: 250 000. Sheet 41 G: Alpena. 3. Edition. Canada Center for Mapping, Natural Resources Canada / Center Canadien de Cartographie, Resources naturelles Canada, Ottawa 1996 ( download as .zip archive with GeoTIFF file, approx. 14 MB).