Deck 19: A Hidden Reserve: Groundwater

Question 1

The majority of liquid fresh water within Earth exists in ____________.

A)lakes
B)rivers and streams
C)pores within rock and sediment
D)atmospheric clouds

Answer 1

C

Question 2

Dissolution of rock produces ____________.

A)primary porosity
B)primary permeability
C)secondary porosity
D)a reduction in primary porosity

Answer 2

C

Question 3

In unfractured rock and sediment,water molecules usually take a ____________.

A)straight path
B)wandering path
C)circular path

Answer 3

B

Question 4

An impermeable layer of rock or sediment is termed a(n)____________ in hydrogeologic contexts.

A)aquitard
B)confined aquifer
C)unconfined aquifer
D)unsaturated zone

Question 5

Primary porosity may be reduced by ____________.

A)compaction of grains
B)cementation of grains
C)A and B are both correct.
D)None of the above are correct.

Question 6

In a humid climate,the topography of the water table ____________.

A)is unaffected by local surface topography
B)precisely mimics the topography of the ground surface
C)is a subdued (less steeply sloping)mimic of surface topography
D)is an exaggerated (more steeply sloping)mimic of surface topography

Question 7

Groundwater ____________.

A)does not affect the porosity of the rock and sediment through which it flows
B)uniformly increases porosity due to dissolution of grains
C)uniformly decreases porosity due to deposition of minerals into pores
D)may increase or decrease porosity through dissolution or deposition

Question 8

Perched water tables occur ____________.

A)above the regional water table,within permeable rock or sediment
B)above the regional water table,within impermeable rock or sediment
C)below the regional water table,within impermeable rock or sediment
D)below the regional water table,within permeable rock or sediment

Question 9

Material through which water readily flows is termed ____________.

A)fluent
B)porous
C)permeable

Question 10

Unless it has recently rained,there is no water within pores in the unsaturated zone.

Question 11

If an intrusive igneous rock is unfractured,it serves as a(n)____________ in local hydrogeology.

A)aquifer
B)aquitard
C)artesian well
D)perched aquifer

Question 12

If a material is porous,it ____________.

A)will be permeable as well
B)will be impermeable
C)may be permeable or impermeable

Question 13

If a material is highly permeable,it ____________.

A)must be porous
B)cannot be porous
C)must be fractured
D)must either have substantial porosity or be fractured

Question 14

A body of permeable rock or sediment,in which the water table resides,is termed a(n)____________.

A)aquitard
B)confined aquifer
C)unconfined aquifer
D)unsaturated zone

Question 15

Rock or sediment with water-filled pores,wherein upward percolation is blocked by an overlying,impermeable layer is termed a(n)____________.

A)aquitard
B)confined aquifer
C)unconfined aquifer
D)unsaturated zone

Question 16

Unconsolidated sediment typically has greater porosity than lithified rock that forms from it.

Question 17

Which list correctly orders the three types of subsurface water from shallowest to deepest?

A)groundwater,soil moisture,vadose zone water
B)soil moisture,groundwater,vadose zone water
C)groundwater,vadose zone water,soil moisture
D)soil moisture,vadose zone water,groundwater

Question 18

Rock or sediment between the water table and the land surface represents a(n)____________.

A)aquitard
B)confined aquifer
C)unconfined aquifer
D)unsaturated zone

Question 19

Sinkholes are a concern primarily for residents whose dwellings are constructed atop ____________.

A)sandstone
B)shale
C)limestone
D)granite

Question 20

Well-sorted sediments typically have ____________ porosity compared to poorly sorted sediments.

A)greater
B)less
C)approximately the same

Question 21

If groundwater is clear,it can be assumed that it is drinkable.

Question 22

An artesian well is one that ____________.

A)discharges groundwater at ground surface without pumping
B)has its intake sited within the saturated zone of an unconfined aquifer
C)has intake sited within the unsaturated zone of an unconfined aquifer
D)has its recharge area at an elevation below sea level

Question 23

Which statement about recharge areas is NOT true?

A)Recharge areas typically are elevated with respect to neighboring areas.
B)Recharge areas are regions of relatively high precipitation.
C)Recharge areas are the same as discharge areas.
D)Recharge areas are areas where water infiltrates the sediment from above.

Question 24

Extensive pumping of fresh groundwater from a coastal aquifer can induce ____________.

A)saline intrusion;with time the well will start to deliver saline water
B)saline expulsion;with time the fresh water/saline water interface within the aquifer will be pushed downward and seaward

Question 25

The elevation of the water table ____________.

A)is a constant for a given area so long as the topography remains the same
B)may rise during times of drought and sink during rainy periods
C)may rise during rainy periods and sink during droughts

Question 26

Water flowing from hot springs ____________.

A)contains more dissolved minerals than water emanating from cool springs
B)contains less dissolved minerals than water emanating from cool springs
C)is never hotter than 40°C,so it is always safe to bathe in
D)only occurs in regions of active volcanic eruption

Question 27

Hard water results from relatively high concentrations of dissolved ____________.

A)calcium and magnesium
B)francium and cesium
C)sodium
D)potassium

Question 28

Land subsidence is likely when ____________.

A)groundwater recharge occurs
B)the Ca and Mg content of groundwater increases
C)the water table changes
D)discharge lowers the water table

Question 29

As a rule,groundwater always flows from areas ____________.

A)of greater elevation to those of lesser elevation
B)of greater water pressure to those of lesser water pressure
C)of greater hydraulic head to those of lesser hydraulic head
D)near streams to areas beneath mountain ranges

Question 30

The rate of groundwater flow per unit area through a body of rock or sediment depends ____________.

A)only on the slope of the water table locally
B)only on the porosity of the rock or sediment
C)on the slope of the water table and the porosity of the rock or sediment
D)on the slope of the water table and the permeability of the rock or sediment

Question 31

Pumping vast quantities of water locally ____________.

A)raises the local water table
B)lowers the local water table,forming a cone-shaped depression
C)lowers the local water table,forming a cylindrical depression
D)does not affect the water table

Question 32

The relationship governing the rate of groundwater flux was discovered by ____________.

A)Alfred Wegener
B)Isaac Newton
C)Henri Darcy
D)Charles Richter

Question 33

Groundwater mining refers to ____________.

A)acid drainage from mines polluting groundwater
B)legal squabbling over groundwater rights ("It's mine!")
C)pumping out water faster than it can be replenished by recharge
D)prospecting an area to find a suitable spot for a well

Question 34

A dry well will always result whenever the base of the well is above the water table.

Question 35

The city of Venice,Italy,has largely submerged beneath the sea because of ____________.

A)polar ice caps melting due to global warming
B)extensive nearby groundwater mining and sediment compaction
C)tectonic forces related to the gradual,ongoing collision of Africa and Europe
D)None of the above are correct;Venice was built underwater during the Middle Ages.

Question 36

Freshwater lakes are always discharge areas.

Question 37

Groundwater:

A)rarely if ever contains dissolved ions
B)dissolves calcite and limestone
C)can contain dissolved minerals but can never precipitate minerals out of solution
D)can precipitate minerals but only if the ions that would form the mineral in question are undersaturated in the water

Question 38

An ordinary (water-producing)well is likely to result when the base of the well extends below the water table.

Question 39

A periodic explosive eruption of steam and water from within the ground up through the surface is termed a ____________.

A)flowing artesian well
B)geyser
C)spring
D)recharge area

Question 40

Any place where groundwater naturally flows out of the surface of Earth is termed a ____________.

A)flowing artesian well
B)geyser
C)spring
D)recharge area

Question 41

The majority of large cave and karst systems have resulted from ____________ etching into ____________.

A)carbonic acid;limestone
B)ascorbic acid;dolostone
C)phosphoric acid;shale
D)sea water;rock salt

Question 42

Besides its immense size,what else is unusual about Carlsbad Caverns in southeastern New Mexico?

A)Geologists think the system was produced by sulfuric acid rather than carbonic acid.
B)The caverns are within a deposit of rock salt rather than limestone.
C)The caverns were formed within the span of just a few days in 1937.
D)Although there are conduits to the surface,the caverns do not host a population of bats.

Question 43

Bioremediation of contaminated groundwater involves ____________.

A)introduction of laboratory-cultured viruses that can dissolve the plume
B)pumping nutrients into a contaminant plume to help local bacteria metabolize the plume
C)pumping out the contaminated groundwater and using it to irrigate genetically modified crops

Question 44

Topography dominated by depressions formed by the collapse of caves is termed ____________.

A)valley and ridge
B)Karst
C)horst and graben

Question 45

Most dissolution of bedrock to form caves takes place ____________.

A)above the water table
B)just below the water table
C)greater than 10 m below the water table