The Pacific Ocean is surrounded by an almost continuous chain of volcanoes. This is known as the ring of fire because of the region's frequent earthquakes and volcanic eruptions. The chain passes along the west coast of North and South America, from the Aleutian Islands to the south of Japan. From Indonesia it extends to the Tonga Islands and to New Zealand. The rocky outer layer of the Earth is broken into about a dozen separate rigid blocks, or plates. The separate plates under the Pacific Ocean and under the continents and the islands that surround the ocean move at different rates. This causes strong disturbances that lead to earthquakes and volcanoes. |