Water Cycle & WeatherChapter 6

L1 Where is Earth’s water?Earth – The water planet– People use water to travel– ¾ of surface is covered by water– It provides a home & food– 3 states of water

• Solid (frozen)• Liquid (melted)• Gas (invisible water vapor)

Atlantic & Pacific Oceans

Arctic & Indian

Southern Ocean

< 1%

• Oceans • Seas

97%

• Lakes • Rivers

“Water, water, everywhere, Nor any drop to drink”

Salt Water Fresh Water

Salt v. Fresh• Most of the fresh

water is frozen in the polar ice caps and glaciers

• You cannot drink salt water

• It has dissolved solids in it– Salt from rocks &

soil– Rivers carry salt to

the ocean– We use ocean salt

on food

Water table

Saltiness

MORE• Warm places where water

evaporates quickly allows more salt to be quickly left behind (salt does not evaporate)

• Red Sea is very salty because there are deserts on three sides

• Most of Earth’s water is salty ocean water

LESS• Ocean water is less salty

near the North and South Poles where the water evaporates less quickly

• Fresh water is found in glaciers and ice caps but it is not safe to drink

• Safe fresh water is found underground or in lakes, rivers, and streams

L2 Water Cycle• Water is recycled• No new water is created• Water is cleaned through the water cycle• Water is always moving– The movement is called the water cycle

Water Cycle

The Water Cycle

• Evaporation – process of changing liquid water to water vapor when it is heated

• Condensation – process of water vapor becoming liquid water when it cools

• Precipitation - any form of water that falls to Earth

Sun’s Energy = powers the water cycle

Review

Earth’s Atmosphere

• The protective blanket that surrounds Earth

• It has mass and takes up space

• Is a mixture of gases• The layer closest to us

has water vapor• Gravity pulls the mass

of air to the surface

Air Pressure• Air pressure is all around us• It pushes down, up, and sideways• Air pressure changes with temperature• It becomes more or less dense, creating high or low

pressure• These changes cause movement• As the movement changes, the weather changes

L3 Air Masses