Structure of the Hydrosphere

Transcription

1 Structure of the Hydrosphere

2 Water Cycle

3 Evaporation The sun s energy heats water molecules on the water s surface. Some of the water s molecules absorb enough energy to change state and evaporate.

4 Water, Animals, and Plants Large amounts of water evaporate from the surfaces of oceans, large lakes, and rivers. This deer and this bird are exhaling small amounts of water vapor. Water evaporates from plants. Water vapor is given off from small holes on the underside of the leaves. This process is called transpiration.

5 Condensation As the water vapor rises, it cools and condenses into liquid water droplets. These condensed water droplets clump together to form clouds.

6 Precipitation Eventually the water droplets become heavy enough to fall back on Earth as droplets. Precipitation may fall in the form of rain, snow, or hail.

7 Runoff and Groundwater When precipitation falls on land, it runs off the surface and into lakes and rivers. Some water trickles down into the soil to become groundwater, which eventually flows to rivers, lakes, and the ocean. The total amount of water has remained constant for millions of years. A water molecule in the Rio Grande may end up as snow on the Alps in Italy. This recycling process ensures that, worldwide, amounts of evaporation and precipitation are equal over time.

8 The Water Cycle QL #66 What is the hydrologic cycle? The hydrologic cycle indicates the various paths water may take as it moves between the atmosphere and earth s surface. The major processes are evaporation, condensation, precipitation, infiltration, surface runoff, and evapotranspiration.

9 Question 2 Where else, other than earth s surface, might you expect to find water? A significant amount of water can be found underground

10 Question 3 What is the driving force behind the hydrologic cycle? Explain. The sun is the driving force behind the hydrologic cycle. Heat from the sun causes surface water to evaporate/transpire. In addition, differential heating of the atmosphere causes air currents, which circulate the water throughout the atmosphere. Evaporated ocean water generally precipitates to earth s surface over land, fueling runoff and infiltration.

11 Question 4 Describe ways in which humans can interfere with the normal flow of water. Explain the negative effects of these activities on the hydrologic cycle. Suggest ways to remedy negative impact. Large cities and urban sprawl can drastically affect local climate, altering normal precipitation patterns.

12 Question 4, cont. Paved surfaces and loss of vegetation act to increase runoff. As a result, infiltration decreases and groundwater becomes depleted. Negative impacts on the hydrologic cycle may be remedied by increasing efficiency of water usage and waste removal, reducing paved areas, collecting and retaining runoff, and selectively planting water-efficient crops.

13 Question 5 Explain why drops of water appear on the side of a soda can after it has been removed from a refrigerator and placed on a kitchen counter. The temperature of the soda can is significantly lower than the temperature of the surrounding air. This difference causes the water vapor in the air to condense on the sides of the can.

14 Question 6 Where does the rain go? Rain can fall into the ocean. It may evaporate and return to the atmosphere, condense, and return to Earth as precipitation. Rain can fall on the ground and make its way, through runoff, to a lake or river. It may end up in the ocean or it might infiltrate the ground and become part of the groundwater supply. Water can be removed from rivers, lakes, or underground aquifers and used for human consumption, industrial purposes, or irrigation. Afterwards, wastewater may re-enter the cycle via runoff or ground infiltration.

15 Page 151 CO: SWBAT describe the structure of the hydrosphere. LO: SWBAT describe how the demand for freshwater threatens the supply of freshwater.

16 Key Words Hydrosphere Salinity Glacier Groundwater Aquifer Wetland Watershed River Tributaries Lake

17 Getting the Idea Earth s continent are surrounded by water. Oceans cover more than two-thirds of the surface. On land, water flows in rivers and streams, and fills up lakes and ponds. Wetlands hold water like a sponge. Water trickles through rock underground to form groundwater.

18 The Hydrosphere The part of the Earth that contains water Most is in liquid form 97% is salt water 3% is fresh water frozen in polar ice caps, glaciers, snow, and permafrost Liquid water is found in groundwater, lakes, wetlands, rivers, and the atmosphere

19 Fresh water 3% Ice 69% Salt Water 97% Groundwater 30% Lakes, rivers, atmosphere, etc 1%

20 The Global Ocean Oceans cover about 71% of Earth s surface Pacific Atlantic Indian Arctic

21 Pacific Ocean Largest and deepest ocean Surface area of 165 million square kilometers Average depth of 4282 meters Mariana Trench meters deep

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23 All the Rest Atlantic Ocean 2 nd largest Half the volume of Pacific Indian Ocean 3 rd largest Between Africa, Australia, and Asia Arctic Ocean Smallest Most covered by sea ice

24 Salinity Concentration of dissolved salts contained in a liquid Increases as more salts are dissolved in water Ocean water has a salinity of about 3.5% 86% sodium chloride, or table salt

25 Ocean Temperature Depends on latitude and depth Warmer at equator and near freezing at the poles Sun warms upper layer of ocean water to a depth of 300 meters

26 Freshwater Resources Most freshwater frozen in polar ice caps Large amounts of water in glaciers Mass of ice and snow that moves slowly over Earth s surface

27 Groundwater Makes up one-third of Earth s fresh water Located below surface Forms when surface water moves down through soils and sediment to collect in spaces between underground rock particles

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29 Aquifer A rock layer that stores water and allows water to flow through it Source for drinking water and water for irrigation Brought to the surface by wells

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31 Wetlands Land areas that remain wet for all or part of the year Act as sponges Collecting and holding rainwater to prevent flooding Filter pollutants and sediment out of water Improves the quality of water that will eventually become drinking water

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34 Watersheds An area of land where precipitation collects and then drains into a single collection place Sometimes called drainage basins Main function to move water from higher to lower elevations

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36 North Carolina s Surface Waters A river is a large, flowing stream of water that is fed by other smaller streams, or tributaries. NC contains 17 river basins Cape Fear River Basin is the largest Covers 9324 square miles of land area Contains streams that drain 29 of NC s 100 counties New River is one of the oldest rivers in the world

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39 North Carolina s Surface Waters Lakes Low area of land where surface water run-off accumulates Vary greatly in size Provide drinking water to cities and towns

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41 Lesson Review Where is most of the fresh water on Earth located? A. In the oceans B. In polar ice caps C. In rivers and streams D. In groundwater

42 Question 2 Which of the following affect ocean water temperature? A. Latitude and longitude B. Depth and distance from land C. Latitude and depth D. Wind and rain

43 Question 3 What are two sources of fresh water used by cities for drinking water? A. Glaciers and lakes B. Rivers and ocean water C. Wetlands and polar ice D. Aquifers and rivers

44 Discussion Question Why might groundwater be cleaner than surface water?