Distribution of Earth’s Water

Distribution of Earth’s Water The Oceans Water covers about 75% of the Earth’s surface 97% is salt water 3% is fresh water only 1% of fresh water can be used • There are 4 major bodies of water: • Atlantic Ocean • Pacific Ocean • Indian Ocean • Arctic Ocean

Ice- 76% of fresh water - Most of Earth’s fresh water is locked in thick sheets of ice near the North and South Poles. - Icebergs – huge chunks of floating ice made of fresh water. Rivers and Lakes • .34% of fresh water • Very little fresh water but important to people who live near them. • Groundwater • - 23% of fresh water (shallow and deep combined) • - Water fills the cracks and spaces in underground soil and rock layers.

Surface Water River Systems a. Tributary – streams and smaller rivers that feed into a main river b. Watershed – land area that supplies water to a river system. c. Divide – separates one watershed from another by a ridge of land • Pond • a. Body of fresh, standing water • b. Smaller than lakes – sunlight reaches the bottom • c. Formed when water collects in hollows or low-lying areas of land • d. Home too many animals including frogs, crayfish, sunfish, water lilies, algae, etc.

Lakes- Body of fresh water that no sunlight reaches the bottom- Deep and big- Formed two ways Same as a pond Powerful forces that shape Earth’s surface such as ice depressions, crust movement or volcanoes Wetlands – a land area that is covered with water during part or all of the year. • 3 types • Marshes – grass covered by shallow water • Swamps – flooded forests with trees – usually in warm, humid climates • Bogs – depression from ice sheets – usually in cold climates

Water Underground Movement • Permeable – water runs through the ground • Gravel • Impermeable – water cannot pass through easily • Clay • Granite • Zones • Saturated – soil is totally filled with water • Unsaturated – soil can still accept water

Ground water • Springs – ground water bubbles or flows out of cracks in rock to Earth’s surface • Aquifer – underground rock or sediment that holds water • Well – channel dug into an aquifer to provide a supply of water • Geyser – hot spring from which water periodically erupts out

Using Freshwater Resources How People Use Fresh Water • Household purposes • Industry • Transportation • Agriculture • Irrigation – supplying water to areas of land to make them suitable for growing crops • Recreation

Conserving WaterReduceRecycleReuse Pollution – addition of any substance that has a negative effect on water or the living things that depend on the water

Distribution of Earth’s Water