Niue, a raised coral island
Niue is a raised coral island fourteen miles long and ten miles wide and bordered nearly all the way around by sea cliffs. Its surface consists of several plateaus or terraces rising one above the other, the highest standing about 200 feet above sea level. The island is composed entirely of limestone made of coral, shells, and plants which grew on a coral reef before it was raised to its present position. The soil is decomposed limestone and, though thin, is rich and favorable for the growth of plants.
There is abundant rainfall, but the water quickly runs into the ground through caves and open cracks in the limestone, and for drinking and cooking the natives use either rain water or the brackish water obtained from caves. There are many times of drought. There are but few kinds of trees on the island, but because of the rich soil they may grow luxuriously. Hardwood trees suitable for making small canoes are present. Pandanus and coconut are the principal plants, which serve alike for food, clothing, and building material. Fish and other sea foods are plentiful.
Raised coral islands, like Nauru, Loyalty, Vavau, and Makatea, may support a fairly large population after food plants introduced from other islands have been established.
Groups of Pacific islands
The Pacific oceanic islands are so numerous that it has been found convenient to consider them as three groups of islands: Polynesia, Melanesia, and Micronesia. Each group contains volcanic islands, coral islands, and raised coral islands. In each group there are different plants and animals and different races of men. Hawaii includes the northernmost islands of Polynesia.