Earth and Space Science / Unit 6: Water on Earth and the Oceans
6.2 Groundwater
Notes
Groundwater is water in pores and cracks under the surface.
- The water table is the top of the saturated zone. Above it is the unsaturated zone.
- An aquifer is rock or sediment that holds and transmits usable water. Porosity is the amount of open space; permeability is how easily water flows through.
- Sand and gravel are porous and permeable; clay is porous but has low permeability.
- A well reaches below the water table. Pumping faster than recharge lowers the water table.
- Groundwater dissolving limestone makes caves and sinkholes.
Practice
The top of the saturated zone is called the:
The water table separates saturated and unsaturated ground.
Which material is the most permeable?
Large connected pores let water flow freely.
Caves and sinkholes are most common in areas of:
Slightly acidic groundwater dissolves limestone.
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