Eventually, slow movements of the Earth’s crust broke apart Pangaea into several pieces that began to drift apart. Scientists say that millions of years ago, there was only one large continent. Some formed as Earth’s shifting continents broke apart. Continental islands (1) were once connected to a continent. Island Formation There are six major kinds of islands: continental (1), tidal (2), barrier (3), oceanic (4), coral (5), and artificial (6). Because of isolation, many islands have also been home to some of the world’s most unusual and fascinating wildlife. For centuries, islands have been stopping places for ships. On another island, Manhattan, rise the towering skyscrapers of the financial capital of the world, New York City. Tokyo, one of the world’s largest cities, is on the island of Honshu in Japan. Others are among the most crowded places on Earth. Many islands are little more than barren rock with few plants or animals on them. Other islands, such as the Greek islands known as the Cyclades in the Aegean Sea, are found in closely spaced groups called archipelagoes. Many islands, such as Easter Island in the South Pacific Ocean, are thousands of kilometers from the nearest mainland. Others, such as Tahiti, lie in warm, tropical waters. state of Alaska, are cold and ice-covered all year. Some islands, such as the Aleutian Islands in the U.S. Greenland, for example, covers an area of about 2,166,000 square kilometers (836,000 square miles). Islands in rivers are sometimes called aits or eyots. These tiny islands are often called islets. Many islands are quite small, covering less than half a hectare (one acre). They vary greatly in size, climate, and the kinds of organisms that inhabit them. There are countless islands in the ocean, lakes, and rivers around the world. Australia, the smallest continent, is more than three times the size of Greenland, the largest island. Continents are also surrounded by water, but because they are so big, they are not considered islands. An island is a body of land surrounded by water.
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