Geologically, a high island or volcanic island is an island of volcanic origin. The term can be used to distinguish such islands from low islands, which are formed from sedimentation or the uplifting of coral reefs[1] (which have often formed on sunken volcanos).

Moorea, a high island of volcanic origin where the central island is still prominent
Stromboli is one of the eight Aeolian Islands, a volcanic arc north of Sicily

Definition and originEdit

There are a number of "high islands" that rise no more than 1 metre (3 ft 3 in) above sea level, often classified as "islets or rocks", while some low islands, such as Banaba, Henderson Island, Makatea, Nauru, and Niue, as uplifted coral islands, rise over 50 metres (160 ft) above sea level.

The two types of islands are often found in proximity to each other, especially among the islands of the South Pacific Ocean, where low islands are found on the fringing reefs that surround most high islands. Volcanic islands normally arise above a hotspot.

HabitabilityEdit

High islands above a certain size usually have fresh groundwater, while low islands often do not, so high islands are more likely to be habitable.

See alsoEdit

  • Archipelagic apron – Fan-shaped gently sloping region of sea floor found around oceanic islands
  • Atoll – Ring-shaped coral reef
  • Canary Islands – Spanish archipelago and region in the Atlantic Ocean
  • Galápagos Islands – Ecuadorean archipelago and protected area
  • Guyot – Isolated, flat-topped underwater volcano mountain
  • Krakatoa Archipelago
  • Seamount – Mountain rising from the ocean seafloor that does not reach to the water's surface
  • Volcanic arc – Chain of volcanoes formed above a subducting plate

ReferencesEdit

  1. ^ Murphy, Raymond E. (July 1949). ""High" and "Low" Islands in the Eastern Carolines". Geographical Review. American Geographical Society. 39 (3): 425–439. doi:10.2307/210643. JSTOR 210643.

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