Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
AIM: How does Earth’s water move through the Water Cycle? Earth’s surface is covered mainly by water. • Oceans cover about 70% of our planet’s surface. What is the Water Cycle? Earth has been recycling its water supply for 4 billion years. • The Water Cycle is the continuous process by which water moves from Earth’s surface to the atmosphere and back. • Driven by energy from the SUN. 3 3 2 Processes of the Water Cycle 1. The Sun heats up the water in Earth’s oceans and lakes. Processes of the Water Cycle 2. Evaporation: liquid water changes to a gas called water vapor. Processes of the Water Cycle • Transpiration: water vapor is released by plants. Processes of the Water Cycle • Respiration: As animals breathe small amounts of water vapor are released. Processes of the Water Cycle 3. Condensation: • Warm air carries water vapor upward. • The air cools and condenses into liquid water. • Convection: Warm air rises and cold air sinks. • Tiny droplets of water clump together around tiny dust particles in the air, forming clouds. Licancabur Volcano is located on the border between Chile and Bolivia. • If a cloud is on, or just above, Earth’s surface, it is called FOG. Processes of the Water Cycle 4. Precipitation: • As more water vapor condenses, the drops of water grow larger and heavier. • The heavy droplets fall as precipitation (rain, snow, sleet, hail). Processes of the Water Cycle 5. The precipitation that falls on land may: • soak into the soil and become groundwater OR • Run off the land, eventually flowing back into the ocean. Water that falls on the surface may run off into rivers and streams, eventually flowing back to a lake or ocean. Water Cycle Video How is Earth’s Water Distributed? • About 97% of Earth’s water is salt water found in oceans. • Only 3% is freshwater. How is Earth’s Water Distributed? • Oceans: the Pacific, Atlantic, Indian, and Arctic Oceans are all interconnected, covering the majority of Earth’s surface. How is Earth’s Water Distributed? • Ice: most of Earth’s freshwater is locked in thick sheets of ice near the Earth’s poles. How is Earth’s Water Distributed? • Rivers and Lakes: Only 0.02% of Earth’s water, but an important source of freshwater for people who live near them. The Great Lakes contain almost 20% of all the water in Earth’s freshwater Lakes How is Earth’s Water Distributed? • Groundwater: water that fills the cracks and spaces in underground soil and rock layers.