Chapter 2 Section 1Chapter 2 Section 1

The Water PlanetThe Water Planet

Water CycleWater Cycle• As we already know, our planet is 70% As we already know, our planet is 70%

waterwater• As a liquid, Water is in the lakes, streams, As a liquid, Water is in the lakes, streams,

rivers, and oceans but it is also in the air rivers, and oceans but it is also in the air around us in the form of _______________around us in the form of _______________

• _______________ - water in the form of a gas _______________ - water in the form of a gas • Glaciers also hold earths water as a solid.Glaciers also hold earths water as a solid.• Even the human body is about 60% water. Even the human body is about 60% water.

The Water CycleThe Water Cycle

What three forms does What three forms does water on earth come water on earth come

in?in?

• Liquid Liquid – rivers, streams, lakes, and – rivers, streams, lakes, and oceansoceans

• GasGas – water vapor – water vapor

• SolidSolid - glaciers - glaciers

Water CycleWater Cycle

• The amount of water on the The amount of water on the earth’s surface does NOT change.earth’s surface does NOT change.

• It does however move around in It does however move around in the ____________________. the ____________________.

• The water cycle moves the earth’s The water cycle moves the earth’s water from the oceans and other water from the oceans and other bodies of water, to the air, and bodies of water, to the air, and then back down to the oceans then back down to the oceans again. again.

EvaporationEvaporation

EvaporationEvaporation – the sun’s heat – the sun’s heat turns liquid into a gasturns liquid into a gas

This gas is known as This gas is known as ____________________________________

Another word for water vapor is Another word for water vapor is ________________________________________

Temperature determines how much Temperature determines how much water vapor the air can hold.water vapor the air can hold.

EvaporationEvaporation

Critical Thinking Critical Thinking QuestionQuestion

•What kinds of What kinds of temperatures can hold temperatures can hold more water vapor, cold or more water vapor, cold or hot?hot?

AnswerAnswer

•HOTHOT

• Warmer temperatures can hold Warmer temperatures can hold more humidity. This is why we more humidity. This is why we have sticky, hot days in the have sticky, hot days in the summer. The sun rays are summer. The sun rays are stronger and the temperature is stronger and the temperature is warmer perfect for evaporation warmer perfect for evaporation and humidity. and humidity.

CondensationCondensation

The warm evaporated air rises as The warm evaporated air rises as it rises, it also coolsit rises, it also cools

As the water vapor cools, it turns As the water vapor cools, it turns back into a liquidback into a liquid

This process of water vapor This process of water vapor cooling and then turning back into cooling and then turning back into a liquid is calleda liquid is called

CONDENSATION.CONDENSATION.

CondensationCondensation

• Condensation forms clouds. Condensation forms clouds.

• As the water vapor turns back As the water vapor turns back into a liquid, during into a liquid, during condensation, it forms tiny condensation, it forms tiny droplets of water. This water droplets of water. This water combines to form clouds. combines to form clouds.

CondensationCondensation

PrecipitationPrecipitation

• These tiny droplets of water will fall back These tiny droplets of water will fall back to the earth’s surface in the process to the earth’s surface in the process known as Precipitation. known as Precipitation.

• The water can fall back to the earth’s The water can fall back to the earth’s surface as:surface as:

• RainRain• SnowSnow• Sleet – frozen rain that makes an icy Sleet – frozen rain that makes an icy

coating, usually comes in winter coating, usually comes in winter • Hail – frozen rain – usually comes in Hail – frozen rain – usually comes in

spring, summerspring, summer

PrecipitationPrecipitation

Collection ( run-off)Collection ( run-off)

• As the precipitation hits the As the precipitation hits the earth’s surface it will then soak earth’s surface it will then soak back into the ground in a back into the ground in a process known as process known as collection.collection.

•Rivers, and streamsRivers, and streams then carry then carry the water that soaked into the the water that soaked into the ground back to theground back to the oceans and the oceans and the cycle starts over again.cycle starts over again.

Collection Collection

QuestionQuestion

•What are the 4 steps to What are the 4 steps to the water cycle?the water cycle?

AnswerAnswer

•EvaporationEvaporation

•PrecipitationPrecipitation

•CondensationCondensation

•CollectionCollection

Water ResourcesWater Resources

•Tell me how many Tell me how many different ways you use different ways you use

water every day?water every day?

Critical Thinking Critical Thinking QuestionsQuestions

•If the earth is made up of If the earth is made up of 70%70% water, then why is water, then why is there so much concern there so much concern over the shortage in over the shortage in water?water?

AnswerAnswer• It is true the earth is more than It is true the earth is more than 70%70%

water which has earned it its name of water which has earned it its name of the BLUE PLANET. the BLUE PLANET.

• However only However only 2%2% of the earth’s water of the earth’s water is freshwater. is freshwater.

• Most of that Most of that 2%2% of water is frozen in of water is frozen in polar ice caps and glaciers. (about polar ice caps and glaciers. (about 80%80% of the 2 %)of the 2 %)

• Only a very small fraction of freshwater Only a very small fraction of freshwater is found in lakes and rivers. is found in lakes and rivers.

FreshwaterFreshwater•We also get freshwater from We also get freshwater from

________________________________

•Groundwater is water that fills tiny Groundwater is water that fills tiny cracks and holes in the rock layers cracks and holes in the rock layers below the surface of the earth. below the surface of the earth.

•There is There is 10X10X more groundwater more groundwater than there is water in lakes and than there is water in lakes and rivers. rivers.

How Do We Get How Do We Get Freshwater?Freshwater?

• We get freshwater from wellsWe get freshwater from wells

• Aquifiers – underground rock Aquifiers – underground rock layers that water flows through. layers that water flows through.

Salt WaterSalt Water

• Almost Almost 98 %98 % of earth’s water is salt of earth’s water is salt waterwater

• The Oceans consist of salt water. The Oceans consist of salt water.

• The Pacific Ocean is the largest The Pacific Ocean is the largest ocean – it is larger than all of the ocean – it is larger than all of the land area on earth combined. land area on earth combined.

• Bodies of water smaller than oceans Bodies of water smaller than oceans are called SEAS, GULFS, BAYS, are called SEAS, GULFS, BAYS, STRAITSSTRAITS