EARTH’S WATERS: 1.2: Fresh Water Flows and Freezes on Earth Divide: A ridge or continuous line of high land, from which water flows in different directions. Drainage basin: (or watershed) is an area into which all of the water on one side of the divide flows.

When it rains in a drainage basin, the water forms streams and rivers or sinks into the ground.

Surface Water Collects in Ponds and Lakes Lakes and ponds form where water naturally collects in low parts of land. Water can fill a lake in a couple of ways: When land is below the level of underground water, the low land fills with water. Can come from a stream or river, and can leave from a lake by a stream or river.

Lake Turnover Turnover: The rising and sinking of cold and warm layers in a lake. Turnovers occur twice a year as the seasons change. The water in a lake is not as still as it appears. The changing temperatures of the seasons affect the water and cause it to move within the lake in a yearly cycle.

Eutrophication Eutrophication: An increase of nutrients in a lake or pond where the pond/lake becomes a meadow. A lake does not remain a lake forever. Through natural processes, (thousands of years) most lakes become meadows, fields, grass, etc. The activity of the life of a lake is based on nutrient levels (eutrophication).

FROZEN WATER 2/3 of the Earth’s fresh water is frozen land near the poles. Glacier: Large mass of ice and snow that moves over land. Two types of glaciers: (1) continental glaciers (cover huge land masses), (2) valley glaciers (in mountains)

ICEBERGS Iceberg: A mass of ice floating in the ocean. Icebergs as tall as 150 ft. above sea level have been found (only about 1/8 can be seen above the surface!) Most of the floating icebergs are below the water’s surface. Water in an iceberg may have been frozen for 15,000 years.