6.3 Water Beneath the Surface

Zone of Saturation

• Zone where all open spaces in sediment and rock are completely filled with water

Groundwater

• Water underground in the zone of saturation

Water table

• The upper level of the saturated zone of groundwater

Porosity

• The volume of open spaces in rock or soil

Permeability

• A measure of a material’s ability to transmit fluids

Aquifer

• Permeable rock layers or sediments that transmit groundwater freely

Spring

• A flow of groundwater that emerges naturally at the ground surface

Geyser

• A hot spring or fountain that ejects water at the intervals

Well

• An opening bored into the zone of saturation

Artesian well

• A well in which the water naturally rises above the level of the water

Cavern

• A naturally formed underground chamber or series of chambers most commonly produced by solution activity in limestone

travertine

• A form of limestone that is deposited by hot springs or as a cave deposit

Karst topography

• An area that has a land surface or topography with numerous depressions called sinkholes

Sinkhole

• A depression produced in a region where soluble rock has been removed by groundwater

Key Concept

• Much of the water in soil seeps downward until it reaches the zone of saturation. The zone of saturation is the area where water fills all of the open spaces in sediment and rock. Groundwater is the water within this zone

Key Concept

• Groundwater moves by twisting and turning through interconnected small openings. The groundwater moves more slowly when the pore spaces are smaller

Key Concept

• A spring forms whenever the water table intersects the ground surface

Key Concept

• Overuse and contamination threatens groundwater supplies in some areas.

Key Concept

• Erosion forms most caverns at or below the water table in the zone of saturation

Key Concept

• Karst areas typically have irregular terrain, with many depressions called sinkholes