Chapter 3 Section 3
About 71 percent of the earth's surface is water covered, and the oceans hold about 9.5 percent of all earth's water. Water also exists in the air as water vapor, in rivers and lakes.
The Water Cycle
Oceans, Lakes, rivers, and other bodies of water make up a part of the earth called hydrosphere. Almost all of the hydrosphere is salt water found in the oceans, seas, and few large saltwater lakes, river, and springs. The total amount of water on the earth does not change, but the earth's water is constantly moving from the oceans to the air to the ground and finally back to the oceans. The water cycle is the name given to this regular movement of water.