Presentation on theme: "Water, water everywhere?"— Presentation transcript:
1 Water, water everywhere? The Water CycleWater, water everywhere?
2 The HydrosphereOceans cover approximately 71% of Earth’s surface.
3 Most of Earth’s water is in the oceans. Less than 3% is freshwater Most of Earth’s water is in the oceans. Less than 3% is freshwater. And less than 1/3 of that can be used as drinking water.
4 The Water CycleThe process by which Earth’s water moves in and out of the atmosphere.
5 The Sun’s RoleThe sun provides the energy that powers the water cycle.
6 EvaporationThe Sun warms Earth’s surface. Water molecules heat up and change from a liquid to a gas (water vapor). The water vapor is circulated by winds and carried upward by rising, warm air.
7 CondensationAs the air carrying water vapor rises and cools it changes back to water droplets and forms clouds.
8 RainPrecipitationWhen the water droplets become large enough they fall back to the surface as precipitation.This can be rain, sleet, snow or hail.SleetSnowHail
9 RunoffIf the precipitation falls on land it may become runoff, water that runs downhill into rivers or streams.
10 GroundwaterIf precipitation seeps (infiltrates) into the earth it may become groundwater, water that has filled pore spaces in the ground.Porosity and saturation effect infiltration. If the surface is non-porous saturated or steep it will become runoff.
11 Transpiration Groundwater is available to plants. Plant’s roots take in water that has seeped into the soil.The water is transported to the leaves and released back into the atmosphere by the process of transpiration.
12 Groundwater seeps through Earth’s crust and may end up in rivers, lakes or the ocean. When this happens the water cycle starts all over again.