Chapter 9

Question 1

Groundwater

Answer 1

Water below the Earth’s surface that fills spaces in regolith, soil and rock.

Question 2

Pores

Answer 2

Spaces within rocks that groundwater is stored in.

Question 3

Porosity

Answer 3

Proportion of pore space in a geologic medium (regolith, sediment or rock)

Question 4

Permeability

Answer 4

Depends on porosity, size of pore spaces, and connectedness of pore spaces

Question 5

Vadose zone

Answer 5

Zone in which air is present in a pore space

Question 6

Permafrost

Answer 6

Pore water may be permanently filled by ice.

Question 7

Water table

Answer 7

Vadose and saturated zones are separated by a boundary

Question 8

Recharge

Answer 8

When water enters the subsurface and becomes groundwater

Question 9

Discharge

Answer 9

Process that returns groundwater to the surface of the Geosphere.

Question 10

Springs

Answer 10

Natural points of groundwater discharge that occur when the water table intersects the land surface

Question 11

Gaining stream

Answer 11

A stream that increases flow downstream due to base flow

Question 12

Losing streams

Answer 12

Streams may decrease in flow downstream if the water recharges groundwater

Question 13

Aquifers

Answer 13

Units within the outermost Geosphere that have sufficient capacity and high enough permeability to supply water at a rate useful to humans

Question 14

Aquitards

Answer 14

Units of geologic media that considerably slow or stop the flow of water

Question 15

Aquicludes

Answer 15

Permeability so low that there is no measurable flow of water through them

Question 16

Unconfined aquifer

Answer 16

Upper boundary is defined by the water table

Question 17

Cone of depression

Answer 17

Drawdown cone produced by pumping water from an unconfined aquifer leads to a lowering of the water table

Question 18

Confined aquifer

Answer 18

Upper boundary is defined by an aquitard or aquiclude

Question 19

Artesian

Answer 19

Water in a confined aquifer may be under pressure

Question 20

Karst topography

Answer 20

Dissolution of limestone and other soluble rock types leads to formation of cave systems, sinkholes and pillars of rock isolated by dissolution of surrounding materials.

Question 21

Fresh water

Answer 21

<1000 ppm dissolved solids

Question 22

Brackish water

Answer 22

1000-10,000 ppm

Question 23

Saline water

Answer 23

10,000-35,000 ppm: same as sea water

Question 24

Brine

Answer 24

> 35,000 ppm

Question 25

Cement

Answer 25

Mineral deposits in small pore spaces

Question 26

Veins or geodes

Answer 26

Cracks precipitated by dissolved mineral material in the saturated zone

Question 27

Dripstone

Answer 27

Calcium carbonate coatings formed in air filled caves

Question 28

Stalactites

Answer 28

Pointed shafts hanging from the ceiling

Question 29

Stalagmites

Answer 29

Rounded domes growing from the cave floor