They cover 72 percent of the Earth's surface, provide food, regulate the climate, and supply mineral sources. Because of the oceans, life itself is possible. An array of captivating color photos, diagrams, and maps introduce this thriving world and the role it plays in our ecology. Probe the extraordinary depths of the briny blue, where the earth's crust constantly moves; undersea volcanoes explode; and amazing creatures survive in hydrothermal vents. Up above, look at shifting coastlines, affected by nature and by human activity. Pictures graphically reveal the results of pollution and capture such breathtaking sights as water spouts growing down from thunder clouds to the sea. Plus: An encyclopedia of marine life, with a list of threatened species. 208 pages (all in color), 8 7/8 x 12.