Chapter 2 Section 1 The Water Planet

Water Cycle As we already know, our planet is 70% water As we already know, our planet is 70% water As a liquid, Water is in the lakes, streams, rivers, and oceans but it is also in the air around us in the form of _______________ As a liquid, Water is in the lakes, streams, rivers, and oceans but it is also in the air 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 Cycle

What three forms does water on earth come in? Liquid – rivers, streams, lakes, and oceans Liquid – rivers, streams, lakes, and oceans Gas – water vapor Gas – water vapor Solid - glaciers Solid - glaciers

Water Cycle The amount of water on the earth’s surface does NOT change. The amount of water on the earth’s surface does NOT change. It does however move around in the ____________________. It does however move around in the ____________________. The water cycle moves the earth’s water from the oceans and other bodies of water, to the air, and then back down to the oceans again. The water cycle moves the earth’s water from the oceans and other bodies of water, to the air, and then back down to the oceans again.

Evaporation Evaporation – the sun’s heat turns liquid into a gas This gas is known as __________________ Another word for water vapor is ____________________ Temperature determines how much water vapor the air can hold.

Evaporation

Critical Thinking Question What kinds of temperatures can hold more water vapor, cold or hot? What kinds of temperatures can hold more water vapor, cold or hot?

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

Condensation The warm evaporated air rises as it rises, it also cools As the water vapor cools, it turns back into a liquid This process of water vapor cooling and then turning back into a liquid is called CONDENSATION.

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

Condensation

Precipitation These tiny droplets of water will fall back to the earth’s surface in the process known as Precipitation. These tiny droplets of water will fall back to the earth’s surface in the process known as Precipitation. The water can fall back to the earth’s surface as: The water can fall back to the earth’s surface as: Rain Rain Snow Snow Sleet – frozen rain that makes an icy coating, usually comes in winter Sleet – frozen rain that makes an icy coating, usually comes in winter Hail – frozen rain – usually comes in spring, summer Hail – frozen rain – usually comes in spring, summer

Precipitation

Collection ( run-off) As the precipitation hits the earth’s surface it will then soak back into the ground in a process known as collection. As the precipitation hits the earth’s surface it will then soak back into the ground in a process known as collection. Rivers, and streams then carry the water that soaked into the ground back to the oceans and the cycle starts over again. Rivers, and streams then carry the water that soaked into the ground back to the oceans and the cycle starts over again.

Collection

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

Answer Evaporation Evaporation Precipitation Precipitation Condensation Condensation Collection Collection

Water Resources Tell me how many different ways you use water every day? Tell me how many different ways you use water every day?

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

Answer It is true the earth is more than 70% water which has earned it its name of the BLUE PLANET. It is true the earth is more than 70% water which has earned it its name of the BLUE PLANET. However only 2% of the earth’s water is freshwater. However only 2% of the earth’s water is freshwater. Most of that 2% of water is frozen in polar ice caps and glaciers. (about 80% of the 2 %) Most of that 2% of water is frozen in polar ice caps and glaciers. (about 80% of the 2 %) Only a very small fraction of freshwater is found in lakes and rivers. Only a very small fraction of freshwater is found in lakes and rivers.

Freshwater We also get freshwater from ________________ We also get freshwater from ________________ Groundwater is water that fills tiny cracks and holes in the rock layers below the surface of the earth. Groundwater is water that fills tiny cracks and holes in the rock layers below the surface of the earth. There is 10X more groundwater than there is water in lakes and rivers. There is 10X more groundwater than there is water in lakes and rivers.

How Do We Get Freshwater? We get freshwater from wells We get freshwater from wells Aquifiers – underground rock layers that water flows through. Aquifiers – underground rock layers that water flows through.

Salt Water Almost 98 % of earth’s water is salt water Almost 98 % of earth’s water is salt water The Oceans consist of salt water. The Oceans consist of salt water. The Pacific Ocean is the largest ocean – it is larger than all of the land area on earth combined. The Pacific Ocean is the largest ocean – it is larger than all of the land area on earth combined. Bodies of water smaller than oceans are called SEAS, GULFS, BAYS, STRAITS Bodies of water smaller than oceans are called SEAS, GULFS, BAYS, STRAITS