Water
Underground
groundwater
permeable
impermeable
saturated zone
unsaturated zone
aquifer
water table
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
• Which wells end in a saturated zone?
• Which well(s) will not provide water?
• How does water enter Aquifer A?
Interesting Sites
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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)