materials that easily allow water to pass through, or permeate.
EX. sand and gravel (large and connnected pores)
material that water cannot pass through easily because they have no pores or cracks (unconnected pores). Once water reaches an impermeable area, it is trapped.
EX. clay and granite
The top of the saturated zone is the water table. If you know the water table of an area, you know how far you must dig to reach groundwater
the unsaturated layer of rocks and soil above the water table (pores contain air as well as water)
any underground layer of permeable rock or sediment that holds water. The water is moving slowly
Where does groundwater come from
it comes from precipitation that soaks into the ground, it trickles downward, following the pull of gravity
Why might a water table rise or fall
-the level of water table follows the shape of underground rock layers.
- it can rise or fall during heavy rainfall or fall during dry weather
Spring and Geysers
-Springs - groundwater comes to the surface through natural processes and flows or bubbles out of cracks in the rock
-Geysers are fountains of boiling hot water and white steam that burst into the air. They are formed when hot water circulates deep underground and begins to rise through narrow passages in the rock. Pressure builds up and increases the narrow openings in the rock. Finally the gases, steam and hot water erupt.