WATER UNDERGROUND

What you will learn Explain that a large portion of the Earth’s

surface is water, consisting of oceans, rivers, lakes, and underground water, and ice.

1. Describe how water moves through underground layers of soil and rock.

Explain how people obtain water from an aquifer.

I. How water moves underground

1. Water underground comes from precipitation and trickles down between particles of soil and through cracks and spaces in layers of rock due to gravity.

A. Effects of Different Materials1. permeable- rocks have large pores that ALLOW water to pass through. (ex: sand, gravel)2. impermeable- rocks have few or no pores or cracks, so rock DOES NOT ALLOW water through (clay, granite).

B. Water Zones

1. When water reaches an impermeable layer, it cannot soak any deeper and begins to fill up spaces above the material.

2. Saturated zone- area of permeable rock that is TOTALLY FILLED, or saturated with water.

3. Water Table- The top of the saturated zone.

4. Unsaturated zone- layer of rocks and soil above the water table.

Review

Tell your neighbor the difference in the saturated and unsaturated zone.

II. Bringing up Groundwater

1. springs- form as groundwater bubbles or flows out of cracks in the rock.

A. aquifer- 1. underground layer of rock or sediment that holds water.2. can range in size from a small underground patch to an area the size of several states.

3. Water is moving, seeping through layers of rock.

4. The rate of movement depends largely on the slope of the aquifer and the permeability of the rocks.

5. Water may travel hundreds of Kilometers and stay in aquifer for thousands of years before coming to the surface.

6. It can provide drinking water. What is an acquifer? What is a spring?

B. Wells1. level of a water table follows the shape of underground rock layers.

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2. Water can rise during heavy rains or snow melts, and fall in dry weather.

3. People can obtain groundwater from an aquifer by drilling a well below the water table.

4. Dry well- well does not reach below the water table, so water cannot be obtained from it.

Why might a water table rise? Fall?

C. Artesian Well1. Artesian well- water rises because of

pressure within an acquifer.2. Groundwater becomes trapped between

two layers of impermeable rock or sediment.

3. The water is under great pressure from rock above it.

4. If rock above it is punctured, the pressure sends water spurting up through the hole.

5. No pump is necessary, pressure does the job.

Contrast

Draw a compare/contrast map about artesian wells and regular wells.

D. Springs and Geysers1. Hot spring- a spring where hot

groundwater bubbles or flows out of cracks in rock. The groundwater is heated by hot rocks deep below it.

2. Geyser- fountain of boiling, hot water and white steam that burst into the air.

a. type of hot spring from which water periodically erupts.

Geysers and Hot Springs

E. Pollution

1. pollutants- substances that cause water pollution.

2. Point source- specific source of pollution that can be identified. (You can point to where it is coming from)

3. Non point source- cannot specifically locate the source of pollution. (ex: farm fields and streets.)

Using and Conserving Water1. People use water for household

purposes, industry, transportation, agriculture, and recreation.

2. What is irrigation? 3. To conserve water:

a. shorter showersb . Water lawn in morning or late in afternoon so sun won’t evaporate water.c. Turn off faucet instead of letting it run while brushing teeth.

Summarizer1. During the winter, you draw your water

from a well on your property. Every summer, the well dries up. What might be the reason for the change?

2. Name one difference in an artesian well and a regular well.

3. Describe the saturated zone and the unsaturated zone.

4. What is the water table?