All the Water All the Water on Earthon Earth

S6E3b: Relate various atmospheric conditions to stages of the water cycle

How is the amount of water How is the amount of water on Earth divided up?on Earth divided up?

3% = Freshwater3% = Freshwater

97% = Saltwater97% = Saltwater

Is most of the water on Is most of the water on Earth freshwater or Earth freshwater or saltwater?saltwater?• Saltwater!Saltwater!

All the Water on All the Water on EarthEarth• SaltwaterSaltwater

• FreshwaterFreshwater

• GroundwaterGroundwater

• Rivers and LakesRivers and Lakes

• Ice caps and glaciersIce caps and glaciers

• Soil and atmosphereSoil and atmosphere

What are 5 Ways You Use What are 5 Ways You Use Water?Water?

Did You Know…Did You Know…• The amount of water on Earth has been The amount of water on Earth has been

the same for eons, however the form and the same for eons, however the form and state of water is constantly changing!state of water is constantly changing!

• The majority of the world’s freshwater is The majority of the world’s freshwater is in ice caps at the North and South poles….in ice caps at the North and South poles….

• So we have to get our water from springs, So we have to get our water from springs, creeks, streams, rivers, lakes and oceanscreeks, streams, rivers, lakes and oceans

Two Characteristics of Two Characteristics of WaterWater1.1.Saltwater is found in oceansSaltwater is found in oceans

2.2.Freshwater is our primary source of Freshwater is our primary source of drinking waterdrinking water

Good to Know!Good to Know!• The Sun is the driving force of the The Sun is the driving force of the

Earth’s weatherEarth’s weather

• And the major source of energy And the major source of energy which ALSO powers the water cycle which ALSO powers the water cycle is the Sun…but we will get to that is the Sun…but we will get to that tomorrow.tomorrow.

Where can we get our hands on Where can we get our hands on this freshwater?this freshwater?¾ Freshwater is Frozen Solid¾ Freshwater is Frozen Solid in ice caps and glaciersin ice caps and glaciers ¼ Freshwater is Liquid underground¼ Freshwater is Liquid underground

A tiny fraction is in lakes & riversA tiny fraction is in lakes & rivers

A smaller fraction is water vapor in A smaller fraction is water vapor in the the atmosphere atmosphere

So…So…• If we had a water bottle and filled it If we had a water bottle and filled it

with 1000mL of waterwith 1000mL of water

• 972 mL would be in saltwater972 mL would be in saltwater

• 28mL would be freshwater28mL would be freshwater

Then…Then…

• Out of that 28mL of freshwaterOut of that 28mL of freshwater

• 23.5mL would be stuck frozen in ice 23.5mL would be stuck frozen in ice caps and glaciers!caps and glaciers!

• 4mL would be underground4mL would be underground

• 2mL would be in lakes and rivers2mL would be in lakes and rivers

• 1mL would be in the soil and air1mL would be in the soil and air

Water never leaves the Earth. It is Water never leaves the Earth. It is constantly being cycled through the constantly being cycled through the atmosphere, ocean, and land. This atmosphere, ocean, and land. This

process, known as the process, known as the water cyclewater cycle, is , is driven by energy from the sun. The water driven by energy from the sun. The water cycle is crucial to the existence of life on cycle is crucial to the existence of life on

our planet. our planet.

The Water CycleThe Water Cycle

During part of the water cycle, the sun heats up liquid water and changes it to a gas by the process of evaporation. Water that evaporates from Earth’s oceans, lakes, rivers, and moist soil

rises up into the atmosphere.

The process of evaporation from plants The process of evaporation from plants is called is called transpirationtranspiration. (In other words, . (In other words,

it’s like plants sweating.)it’s like plants sweating.)

As water (in the form of gas) rises higher in the atmosphere, it starts to cool and become

a liquid again. This process is called condensation. When a large amount of water vapor condenses, it results in the

formation of clouds.

You Know This!You Know This!• Think of it like when you take a showerThink of it like when you take a shower

• The water is HOT (or warm)The water is HOT (or warm)

• Thinking back to evaporation, we know Thinking back to evaporation, we know when the water heats, it turns into a when the water heats, it turns into a vapor and enters the atmospherevapor and enters the atmosphere

• Once this vapor hits your cooler mirror, Once this vapor hits your cooler mirror, it turns into a liquid againit turns into a liquid again

When the water in the clouds gets too heavy, the water falls back to the earth. This is called precipitation.

When rain falls on the land, some of the water is absorbed into the ground forming pockets of water called groundwater. Most

groundwater eventually returns to the ocean. Other precipitation runs directly into

streams or rivers. Water that collects in rivers, streams, and oceans is called runoff.

Show Me You Show Me You Understand!Understand!

• Some of you will receive a card. Some of you will receive a card.

• If you see your part of the water cycle If you see your part of the water cycle happening, hold your card up and tell the happening, hold your card up and tell the class what it is with a definition.class what it is with a definition.

• *Hint: evaporation and condensation *Hint: evaporation and condensation happen quickly together*happen quickly together*

• http://www.pbslearningmedia.org/resource/ess05.sci.ess.watcyc.watercycle/water-cycle-animation/