Deck 17: Water Flowing Underground

Question 1

"The water table always loses water when it is intersected by a stream bed that has eroded to that level." Evaluate this statement.

A) It is true. Water from the water table seeps into the stream and moves downstream.
B) It is partially true. When it rains, the water table gains water through the streambed.
C) It is false. Stream beds cannot erode enough to reach the water table unless there is an existing spring.
D) It is false. Streams receive their water by runoff of precipitation and, in fact, supply water to the water table.

Answer 1

B

Question 2

What lies just above the water table?

A) a layer of shale
B) an unsaturated zone
C) a saturated zone
D) empty cavern space

Answer 2

B

Question 3

Which type of aquifer is most common in the United States?

A) sand and gravel
B) igneous and metamorphic rock
C) sandstone
D) limestone

Answer 3

A

Question 4

Ground water

A) moves short distances through shallow soil horizons and reemerges to join surface runoff in streams.
B) trickles along surfaces of mainly granite rocks.
C) percolates through lava rock to reach the soil below.
D) percolates deep below the surface through open spaces and fractures.

Question 5

Why do some communities inject treated wastewater into aquifers?

A) to recharge it artificially, since nature cannot keep up with urban demands
B) as a convenient place to dispose of water that is not suitable for other uses
C) for storage in a place that is not subject to as much evaporation as a reservoir
D) to prevent flooding due to too much wastewater above the surface

Question 6

Which factor has the greatest influence on how long water spends in an aquifer?

A) porosity
B) permeability
C) elevation difference between recharge and discharge
D) length of flow path

Question 7

Which of the following statements is false?

A) Pressure can move underground water up.
B) Pressure can move underground water horizontally.
C) Pressure can move underground water down.
D) Pressure can move underground water in any direction.

Question 8

What mineral precipitates at travertine springs to create formations?

A) sulfates
B) sulfites
C) calcite
D) halite

Question 9

Which statement about ground water is false?

A) It is pure H2O.
B) It is less quickly affected by pollution sources than surface water.
C) It makes up about 98 percent of Earth's unfrozen fresh water.
D) It is usually a reliable water source.

Question 10

What influences the shape of the cone of depression?

A) the rock type and the depth of permeability
B) the elevation of the aquifer compared to the well depth
C) balance between pumped water and ground-water flow toward well
D) the size of the aquifer

Question 11

Choose the option that puts the rock and sediment types in order from most porous to least porous.

A) shale, sand and gravel, silt and clay
B) silt and clay, metamorphic rocks, volcanic rocks
C) sand and gravel, limestone, shale
D) plutonic rocks, limestone, sand and gravel

Question 12

What causes hot springs?

A) extreme kinetic energy and pressure from emerging water
B) deep circulation of water
C) proximity to tectonic action
D) proximity to magma

Question 13

What is a typical range of pore sizes in rock?

A) 5 micrometers to 100 micrometers
B) 0.1 millimeter to 0.8 millimeter
C) 0.1 millimeter to 3 centimeters
D) 10 millimeters to 5 centimeters

Question 14

Which is not an effect of underground water?

A) mass movement
B) sinkholes
C) caverns in limestone
D) underground pockets that gather petroleum

Question 15

What has caused changes to the water level in the High Plains aquifer?

A) erosion
B) irrigation
C) increasing urban demand
D) tectonic plate movement

Question 16

What kind of path does water follow underground, and why?

A) straight, due to rock layering
B) angled, due to gravity and pressure
C) curved, due to the shape of Earth
D) curved, due to gravity and pressure

Question 17

What creates perched ground water?

A) tectonic plate movement
B) folding action that results in higher pockets
C) patches of low-permeability rock
D) excessive flooding

Question 18

What causes warm springs?

A) extreme kinetic energy and pressure from emerging water
B) deep circulation of water
C) proximity to tectonic action
D) proximity to magma

Question 19

Which of the following cause ground water to flow?

A) kinetic energy and pressure
B) volume and elevation
C) elevation and potential energy
D) potential energy and pressure

Question 20

The direction of ground-water flow between any two locations in an aquifer is determined by comparing the total ________ of the water at each location.

A) elevation
B) pressure
C) energy
D) volume

Question 21

Where is arsenic most likely to be common in drinking water?

A) near industrial plants
B) near large batholiths of metamorphic rock
C) where water flows through volcanic rocks
D) where water flows across the surface for a long distance

Question 22

How is the velocity of underground water measured?

A) with a hydrometer
B) by injecting and tracking a tracer chemical at different points
C) by interpretation of seismic readouts
D) by tracking the progress of a radioactive tracer through the ground

Question 23

Which of the following is not true of hard water?

A) It increases the permeability of rocks.
B) It may add toxic metals to drinking water.
C) It may clog pipes.
D) It decreases the effectiveness of soaps.

Question 24

Figure 17.29
Which of the following states has the most ground water that contains toxic concentrations of arsenic?

A) South Carolina
B) Florida
C) Montana
D) Texas

Question 25

Which of the following is not a reason that the tracer material was found at varying concentrations?

A) impermeability of materials
B) varying pore sizes
C) varying circuitous routes of water molecules
D) spreading out over a large volume of water

Question 26

A water well is contaminated by a nearby pollution source. A consultant suggests drilling a second well to help purify the first well. Evaluate this strategy.

A) This strategy will work to reduce the pollution in the first well by half, since half the pollution will now go to the second well.
B) The strategy will not work because the pattern of flow has been established and the pollution will continue to flow to the first well.
C) The strategy can work if the new well is pumped at a high rate to create a cone of depression deep enough to divert the polluted water.
D) The strategy will only work well if the pollution source has been affected by a well that is drilled into a confined aquifer.

Question 27

Which option is not a piece of knowledge scientists have gained by inference from the Cape Cod experiment?

A) Pollution travels very slowly from its source.
B) Pollution expands in a wide area from its source.
C) Pollution is diluted as it moves away from the source.
D) Pollution cannot be cleaned up once it gets into the ground water.

Question 28

Which of the following is not true of soft water?

A) It requires special filters and chemicals to produce.
B) It may clog pipes.
C) It may add toxic metals to drinking water.
D) It may corrode pipes.

Question 29

What effect do the chemical reactions of ground water have on the porosity and permeability of aquifers?

A) Chemical reactions both increase and decrease the permeability and porosity.
B) Chemical reactions neither increase nor decrease the permeability and porosity.
C) Chemical reactions increase the permeability and porosity.
D) Chemical reactions decrease the permeability and porosity.

Question 30

Which well is least likely to need pumping?

A) a well that reaches water very near the surface at an unconfined sand and gravel aquifer
B) a well that is drilled below a confining shale layer to a confined sandstone aquifer
C) a well that is drilled deep in an unconfined sandstone aquifer
D) any well in a limestone aquifer

Question 31

Which is not one the most common ore deposits that form in sedimentary rocks that is associated with hard-water deposits?

A) zinc
B) copper
C) magnesium
D) lead

Question 32

What ion was used as a tracer in the Cape Cod experiment?

A) chloride
B) bromide
C) dioxide
D) sulfide

Question 33

Which is the primary factor that causes ground water to flow more slowly than surface water?

A) friction
B) temperature
C) pressure
D) small pore sizes

Question 34

Which assumption did the Cape Cod water flow velocity experiment rely upon?

A) Water flows toward the discharge site.
B) Water flows to areas of decreased elevation.
C) Water flows to areas of decreased pressure.
D) Water flows to rock with more open pores.

Question 35

Which type of ground water would have the least amount of dissolved minerals?

A) hot water
B) water from deep in the Earth
C) water that had flowed quickly through the aquifer
D) water that had been underground for a long period of time

Question 36

Excess pumping of fresh water wells in coastal areas may do all of the following except

A) increase the quality of the water.
B) create a deeper cone of depression.
C) draw salt water from the lower aquifer up.
D) draw water that is undrinkable.

Question 37

Which is not a reason that fresh water wells near coastlines abruptly become salty and unusable?

A) As water is pumped from the well, the freshwater runs out and leaves only the salty water from the sea.
B) Salt water is denser than fresh water, so it lays on the lower part of coastal aquifers.
C) Sea water infiltrates underlying pore spaces, making ground water beneath the sea floor salty.
D) As water is pumped from the well, the saltwater part of the aquifer flows up because of decreased aquifer pressure.

Question 38

Contaminants in the water table may do all of the following except

A) precipitate.
B) disappear.
C) sink below the level of the water.
D) float on top of the level of the water.

Question 39

What does not happen as ground water moves toward the surface?

A) It cools slightly.
B) It solidifies.
C) It mixes with shallow water with different chemistry.
D) It reacts with near-surface rocks.

Question 40

"Compared to other ground water, the rate of the Cape Cod experiment area, 0.43 meters per day, is probably faster than average." Evaluate this statement.

A) This is true. The Cape Cod aquifer is made of relatively porous unconsolidated gravel and sand.
B) This is false. Other aquifers might flow as quickly as 0.5 meters per second.
C) Aquifer flow cannot be estimated without repeating a similar experiment in other areas.
D) This is true. The Cape Cod aquifer has a much steeper slope than average.

Question 41

How does gasoline behave when it leaks into the water table?

A) It floats on top of the water table.
B) It sinks to the bottom of the aquifer.
C) It dissolves in the water.
D) It precipitates.

Question 42

The ability of a porous material to permit fluid flow through the material is called

A) porosity.
B) dissolution.
C) permeability.
D) precipitation.

Question 43

Plant roots extract water from

A) streams.
B) below the water table.
C) the saturated zone.
D) the unsaturated zone.

Question 44

How do environmental scientists deal with chemicals that sink to the bottom of an aquifer?

A) They leave them alone because the chemicals have not mixed with the drinking water supply.
B) They add a coagulating chemical to make sure the chemicals solidify and remain deep in the Earth.
C) They create a cone of depression some distance away to suck the contaminant in an opposite direction.
D) They pump them up through a well drilled to the bottom of the aquifer.

Question 45

A body of rock or regolith with sufficient porosity and permeability to provide water in useful quantities to wells or springs is called a(n)

A) aquitard.
B) saturated zone.
C) aquifer.
D) water table.

Question 46

What is MTBE?

A) a pollutant that dissolves in ground water
B) a natural component of gasoline
C) a pollutant that sinks to the bottom of an aquifer
D) a carcinogen that rises to the top of the water table

Question 47

Which of the following states has the most limestone and gypsum karst topography?

A) New Mexico
B) Rhode Island
C) Washington
D) Idaho

Question 48

Judge the following sentence according to the criteria given below. There is a downward limit to which water can descend because porosity and permeability decrease downward in Earth.

A) The assertion and the reason are both correct, and the reason is valid.
B) The assertion and the reason are both correct, but the reason is invalid.
C) The assertion is correct but the reason is incorrect.
D) The assertion is incorrect but the reason is correct.
E) Both the assertion and the reason are incorrect.

Question 49

"Carbon dioxide plays a vital role in dissolving and precipitation of rocks in the formation of karst topography." Evaluate this statement.

A) It is false. The statement should read sulfur dioxide, not carbon dioxide.
B) It is partially true. Carbon dioxide does form acid to aid in dissolving limestone but has nothing to do with precipitation of rocks.
C) It is false. Carbon dioxide does dissolve in water to form acid, but only at the surface where water is exposed to air.
D) It is true. Carbon dioxide plays a vital role in these processes.

Question 50

Water concentrated where low permeability in specific spots create a shallow saturated horizon balanced above the water table is called ________ ground water.

A) balanced
B) perched
C) roosted
D) dwelled

Question 51

How is karst topography defined?

A) rock features formed by sedimentation and precipitation from streams and ground water
B) rock features and drainage patterns formed by glacier action and deposition
C) rock features and drainage patterns formed by dissolution of rock
D) rock features and drainage patterns formed by flowing lava

Question 52

Which of the following rocks would you expect to have the highest permeability?

A) poorly-sorted uncemented sand
B) poorly-sorted cemented sand
C) well-sorted cemented sand
D) well-sorted uncemented sand

Question 53

The surface that marks the top of the ground water is called the

A) water table.
B) saturated zone.
C) unsaturated zone.
D) water layer.

Question 54

Which mineral does not dissolve readily in water?

A) halite
B) gypsum
C) mica
D) calcite

Question 55

Which factor contributes least to the dissolving of subterranean limestone?

A) plant roots release carbon dioxide underground
B) general acidity
C) percolating ground water
D) abrasive rubbing action of pebbles

Question 56

Which state's rocks have almost all been affected by the dissolving effects of water?

A) Idaho
B) Maine
C) Florida
D) North Carolina

Question 57

Ground water can seep out at the surface

A) when the water table is low because the land surface is low.
B) when the water table intersects the ground surface.
C) when the water table is high because the land surface is high.
D) when runoff enters the channel during and shortly after rainfall.

Question 58

Which land feature is not a hint that ground water weathering has been taking place?

A) amphitheatre-like caverns in cliffs
B) fine sand particles
C) underground caverns
D) rock towers

Question 59

Which of the following rocks would you expect to have the lowest permeability?

A) poorly-sorted uncemented sand
B) poorly-sorted cemented sand
C) well-sorted cemented sand
D) well-sorted uncemented sand

Question 60

The permeability of an igneous rock can be increased by

A) sorting.
B) cementation.
C) fracturing.
D) metamorphism.

Question 61

Define a confined aquifer. Are these types of aquifers more or less susceptible to pollution than an unconfined aquifer?

Question 62

Judge the following sentence according to the criteria given below. Ground water acquires the temperature of the warmest rock that it passes through and then cools only slightly as it travels toward discharge at the surface because heat conducts from rock into water more readily than heat conducts from water into rock.

A) The assertion and the reason are both correct, and the reason is valid.
B) The assertion and the reason are both correct, but the reason is invalid.
C) The assertion is correct but the reason is incorrect.
D) The assertion is incorrect but the reason is correct.
E) Both the assertion and the reason are incorrect.

Question 63

If you see a stream that flows year round you know that that stream

A) receives surface water only.
B) receives ground water only.
C) receives ground water and surface water.
D) exists where it rains everyday.

Question 64

Judge the following sentence according to the criteria given below. Ground water moves along the top of the water table from high elevation to low elevation because the slope of the water table determines the direction of ground-water flow.

A) The assertion and the reason are both correct, and the reason is valid.
B) The assertion and the reason are both correct, but the reason is invalid.
C) The assertion is correct but the reason is incorrect.
D) The assertion is incorrect but the reason is correct.
E) Both the assertion and the reason are incorrect.

Question 65

Figure 17.9
According to Figure 17.9, which of the following materials would you expect to have the most sufficient porosity and permeability and be able to provide water in useful quantities?

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

Question 66

The elevation of the water table will rise when

A) recharge equals discharge.
B) recharge is less than discharge.
C) recharge is greater than discharge.

Question 67

Figure 17.9
According to Figure 17.9, which of the following materials would you expect to be the best confining bed?

A) granite
B) gravel
C) fractured basalt
D) sand

Question 68

Ground-water motion is due to potential- and pressure-energy effects. Potential energy is ________ at the surface than at lower elevations below ground. Pressure energy ________ with increasing depth.

A) greater, increases
B) greater, decreases
C) lesser, increases
D) lesser, decreases

Question 69

Although clay has ________ porosity it does not make a good aquifer because it has ________ permeability.

A) low, high
B) low, low
C) high, low
D) high, high

Question 70

Describe how coastal wells abruptly become salty and unusable.

Question 71

What is an aquifer?

Question 72

All of the following are common sources of ground water pollution except

A) leaky underground storage tanks.
B) oil tanker spills.
C) leaky septic systems.
D) landfill leaching.

Question 73

Many municipal water systems use a high water tower to

A) prevent pollution of the water.
B) paint the town's initials.
C) provide potential energy.
D) get the water out of the ground.

Question 74

Significant pumping of ground water can cause land subsidence which is a result of

A) compaction.
B) fracturing.
C) recharge.
D) discharge.

Question 75

Why do we develop a well?

Question 76

Why would we want to be sure to drill into an aquifer to develop a water well?

Question 77

Figure 17.9
According to Figure 17.9, which of the following aquifers would you not expect to find in the state of Nevada?

A) limestone aquifers
B) sandstone aquifers
C) sand and gravel aquifers
D) igneous/metamorphic rock aquifers

Question 78

Caverns form in all of the following rock types except

A) igneous rocks.
B) sedimentary rocks.
C) metamorphic rocks.
D) igneous and metamorphic rocks.
E) igneous and sedimentary rocks.

Question 79

Which of the following features is evidence of ground-water dissolution?

A) sinkholes
B) spits
C) yardangs
D) levees

Question 80

A layer of impermeable material, such as clay, that prevents mixing of the ground water in the aquifers above and below it is called a ________ layer.

A) blocking
B) confining
C) constraining
D) restraining