How Does Water Move through the Ground?
ES1401  Porosity and Permeability

Two separate characteristics of rocks control how effective they are as aquifers:

Porosity is a measure of how much of a rock is open space. This space can be between grains or within cracks or cavities of the rock.
Permeability is a measure of the ease with which a fluid (water in this case) can move through a porous rock.
Tom Grace, TERC
Microscopic structure of shale, sandstone, and limestone with water in pore spaces. Note differences in scale among views of each rock type.

4. Describe how the shape and number of pore spaces affect permeability of these three rock types.

5. Explain why the sandstone had the highest flow rate.

6. Shale is composed of individual particles with pore spaces between them, similar to the structure of sandstone. Why was the flow rate for shale so much lower than for the sandstone?

7. How could limestone's ability to hold and transfer water be increased? 



	

 	

		
			
	

	
	

		 
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