A 'low island' is, in
geology (and sometimes in
archaeology), an
island of
coral origin. The term applies whether the island was formed as a result of
sedimentation upon a
coral reef or of the
uplifting of such islands. The term is used to distinguish such islands from
high islands, whose origins are
volcanic.
This distinction is important to understand, as there are some low islands, such as
Makatea,
Nauru,
Niue and
Banaba, which rise several hundred feet above
sea level, while a number of high islands rise no more than a few feet above sea level, often classified as "
rocks".
Low islands are the kind of islands which ring the
lagoons of
atolls.
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.
Low islands have poor, sandy soil and little fresh water which makes it difficult to farm here. They don't support human inhabitation as well as high islands. The people that do live on low islands survive by mostly fishing.