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Water Underground. How Water Moves Underground. Water underground trickles down between particles of soil and through cracks and spaces in layers of rock. Effects of Different Materials.
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How Water Moves Underground • Water underground trickles down between particles of soil and through cracks and spaces in layers of rock
Effects of Different Materials • Permeable materials have large and connected pores; materials such as sand and gravel allow water to pass through or permeate. • Impermeable materials have few or no pores or cracks; therefore the water cannot pass through easily • Examples: clay and granite
Water Zones • **The area of permeable rock or soil that is totally filled or saturated, with water is called the saturated zone** • **The top of the saturated zone is called the water table** • The area above the water table is called the unsaturated zone
Bringing up Groundwater • In some areas, the water table meets the surface • Aquifers: • Any underground layer of rock or sediment that holds water is known as an aquifer** • Size: small underground patch to the size of several states
Aquifers continued • Functions: drinking water, water for crops, and water for livestock • Rate of Movement: depends on the slope of the aquifer and permeability of rocks
Wells • **People can obtain groundwater from an aquifer by drilling a well below the water table** • If the level of the aquifer drops, a well can run dry • The water table can rise after heavy rain or snow melts
Using Pumps • Mechanical pumps bring up groundwater • If water is pumped out too fast, a well will run dry • New water that enters the aquifer from the surface is called recharge
Relying on Pressure • **In an artesian well, water rises because of pressure in an aquifer** • If groundwater becomes trapped between two layers of impermeable rock or sediment, the pressure sends water spurting up through the punctured hole • No pump is necessary
Springs and Geysers • Sometimes, groundwater comes to the surface through natural processes • When groundwater bubbles or flows out of cracks in the rock it is called a spring • A fountain of boiling water is known as a geyser
Springs and Geysers • The word geyser means gusher • A geyser forms when very hot water that has been circulating deep underground begins to rise through narrow passages in the rock • Provide one example of a geyser: Old Faithful
Interesting Sites • http://unmuseum.mus.pa.us/flash/geyflash.htm • http://www.nps.gov/archive/yell/oldfaithfulcam.htm • http://www.floridasprings.org • www.unitedstreaming.com(Gushing Geysers; Natural Phenomena)
Which wells end in a saturated zone? • Which well(s) will not provide water? • How does water enter Aquifer A?