Download What is the water cycle?

Unit 1 Lesson 2 The Water Cycle
What Goes Up …
What is the water cycle?
• The movement of water between the atmosphere, land, ocean, and living things
makes up the water cycle.
• Rain, snow, and hail fall on the oceans and land. On land, ice and water flow
downhill.
• Water vapor moves upward and is carried great distances by the wind. The wind
also creates ocean currents.
How does water change state?
• Water on Earth is found as a liquid, solid, and gas.
• Water absorbs energy from its surroundings as it melts from solid to liquid.
• Water also absorbs energy as it evaporates from liquid to gas, or when it
sublimates from solid to gas.
• Water releases energy to its surroundings when it condenses from gas to liquid.
• Water also releases energy when it freezes from liquid to solid or deposits from
gas to solid.
• No water is lost during these changes of state.
How does water reach the atmosphere?
• Water reaches the atmosphere as water vapor through evaporation,
transpiration, and sublimation.
• Evaporation occurs when liquid water changes to water vapor.
• Most of the water vapor evaporates from Earth’s oceans.
• Transpiration is the release of water vapor into the atmosphere by plants.
• Sublimation is when solid water changes directly to water vapor without first
becoming a liquid.
• Sublimation can occur when dry air blows over ice or snow, where it is very cold
and the pressure is low.
• Identify each process as evaporation, sublimation, or transpiration.
What happens to water in the atmosphere?
• Condensation is the change of state from gas to liquid. It can occur in the air as
clouds, fog, or mist, or on the ground as dew.
• Precipitation is any form of water that falls to Earth from clouds.
• Rain, snow, and hail are common forms of precipitation.
How does water move on land and in the oceans?
• Streams, rivers, and the water that flows over land are types of runoff. Runoff
flows downhill.
• Some of the water on land seeps into the ground. This process is called
infiltration.
Once undergound, the water is called groundwater. Groundwater also flows downhill.
• Glaciers, which may be called “rivers of ice,” flow downhill and sometimes flow to
the ocean, where pieces may break off.
• Winds move ocean water on the surface in great currents over long distances.
• Cold or salty water will sink in the ocean, forming deep ocean currents that move
large amounts of water.
Water Works
What does the water cycle transport?
• The water cycle moves energy and matter.
• Energy is transported by changes in state and by the movement of water from
place to place.
• Matter is transported all around the world by ocean currents, rivers, and glaciers.
• Identify the processes in the water cycle.