Some interesting and unusual facts about the oceans of the Earth:
1. Over 97 percent of the Earth's water supply is contained in the oceans. Most of the rest is frozen solid in ice sheets and glaciers.
2. The oceans cover seven tenths of the Earth's surface.
3. There are three main oceans: The Pacific, which covers 30 percent of the globe, is twice as large as the Atlantic the second largest, which is in turn slightly larger than the Indian Ocean.
4. Some people say that there are two additional, smaller oceans: the Antarctic, which is connected to the Pacific, Atlantic and Indian Oceans, and the, Arctic, which is an extension of the Atlantic.
5. The average depth of the ocean is 3,800 meters.
6. The Marianas Trench, off the coast of the Philippines, is one of the deepest parts of the ocean. It descends to 11,033 meters - more than 2,000 meters deeper than the height of Mount Everest.
7. The water pressure at the bottom of the Marianas Trench is more than 300 times greater than at the surface.
8. From the coastline of a continent, the continental shelf drops about 1 meter in every 500. This increases to 1 in 40 at the edge of the shelf where the continental slope begins, leading down to the bottom of the ocean.
9. The ocean floor contains a rich, varied a landscape, with flat plains, canyons deeper than the Grand Canyon, and "rivers" of moving sediment.
10. There are 600,000 kilometers of mid-oceanic ridges, as large as the Alps, the Rockies, and the Himalayas.