Volcanic island

For places named High Island, see High Island (disambiguation).

Moorea, a high island of volcanic origin where the central island is still prominent.

Ball's Pyramid, a steep remnant of an oceanic volcano, now forming a small high island or "islet" in the southern Pacific.

In geology (and sometimes in archaeology), a high island is an island of volcanic origin. The term can be used to distinguish such islands from low islands, whose origin is due to sedimentation or uplifting of coral reefs.

Definition and origin

There are a number of "high islands" which rise no more than a few feet above sea level, often classified as "islets or rocks", while some "low islands", such as Makatea, Nauru, Niue, Henderson and Banaba, as uplifted coral islands, rise several hundred feet 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 are normally made over a so-called hotspot.

Habitability for humans

The differences in geology and topography between high and low islands mean a lot, in terms of habitability for humans. High islands above a certain size usually have ground water, while low islands often do not. This hampers or hinders human settlement on many

See also

• Atoll
• Low island

External links

• Micronesian culture: High island and low island cultures at Britannica.com. Retrieved 2011-09-22.