High island
In geology, 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.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 normally arise above a hotspot.Habitability
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.
