1. 6.3 - Groundwater
groundwater is the largest source of available fresh water for humans
groundwater is stored in an aquifer
movement of groundwater depends upon two main factors: porosity & permeability

2. porosity: percentage of a rock that consists of open spaces
permeability: ability of a rock to let water pass through its open spaces (pores)
for a rock to be permeable, the pores must be connected

4. Layers within an Aquifer
zone of aeration: layer where pore spaces in the rock layer contain mostly air
zone of saturation: area below zone of aeration where all the pore spaces are filled with water
top of this zone marks the beginning of the water table

6. wells are drilled down to the water table then water is pumped to the surface

7. if a well is under pressure so that the water comes to the surface without any pumping, it is called an artesian well
forms where the aquifer layer is between two non-permeable layers so squeezes the water out of the well

9. springs form when groundwater naturally comes to the surface without drilling a well
if groundwater is heated by magma before coming to the surface, it is called a hot spring

10. geysers are hot springs that erupt at the surface, throwing steam & water into the air

11. karst topography: irregular surface (topography) due to groundwater chemically weathering the bedrock
usually found in humid (wet) regions underlain by limestone

12. caverns: large cave with many smaller connecting chambers

13. a calcite deposit that hangs from the ceiling is called a stalactite
directly below a stalactite, is another calcite build-up called a stalagmite

14. if a stalagmite and stalactite meet, a column will form
sinkhole: circular depression at the surface that forms when rock is dissolved or a cave collapses