Water Cycle

Water is constantly in flux between evaporation and precipitation. Eighty-nine percent of the water evaporating from the ocean surface (319 x 10¹⁸ g) returns to the ocean as rain. The remaining 11 percent of the evaporation (36 x 10¹⁸ g) is transported by winds over land. To see a diagram of the water cycle, click on the picture below.

Over land, this water from the oceans combines with the water being evaporated from the land surface or transpired by plants into the atmosphere (59 x 10¹⁸ g) to form rain (95 x 10¹⁸ g). Of the rain striking the Earth's surface, some of the water (36 x 10¹⁸ g) runs off or enters the groundwater and is transported back to the ocean.

• What percent of the rain falling on the earth returns to the oceans?
• In the entire scheme of things, how many grams x 10¹⁸ of water is involved in this cycle?

The water cycle is heavily influenced by other factors. The Serengeti is a good example of the seasonality of the water cycle.

• How does the water cycle affect the seasonal migration of animals on the Serengeti?

Properties | Movement | Life | Locomotion | Metabolism | Excretion | Reproduction | Adaptation | Ecology | Map

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© 2004, Arthur L. Buikema, Jr. All rights reserved.