There is no other planet in the entire solar system like Earth. It holds nearly all the liquid water in our solar system! It is this water that allowed life to come into being and spread throughout our planet. These unique oceans exist because the planet’s surface temperature is in the range in which water remains liquid. The temperature range, 0° C to 100° C, occurs rarely in our universe; matter tends to be frozen solids or hot gases.
By looking at a map or globe, one can see that all the oceans are interconnected, and are divided by the continents. The northern parts of the Atlantic and Pacific Oceans which go around the North Pole, form the Arctic Ocean. The southern parts of the Atlantic, Pacific and the Indian Oceans extend around the Antarctic Continent and form the Antarctic Ocean. These five great oceans cover approximately 70% of the surface of the earth.
Many scientists believe that the oceans holds the key to how the earth was formed. One important factor is related to erosion, and the other to the difference in the crust of the earth under land to under the ocean.
Throughout the years, land areas on earth have been changed and worn away by the forces of erosion. If the ocean floor is not as affected by erosion from the wind and water, then it may be closer to its original state. This then, will allow studies to confirm or correct our knowledge of how the earth was formed.
The crust of the earth is thinner under the floor of the ocean than under land areas. It is thought that it would be easier to reach the layer beneath the crust, the mantle, through the ocean floor, though as of this time it is still impossible. This will allow scientists to learn more then they now know about the earth and its origin.
(figure available in print form)