Deck 11: Ground Water

Question 1

Springs may form where a perched water table intersects the surface.

Answer 1

True

Question 2

In confined aquifers the water is under pressure and rises to a level above the top of the aquifer.

Answer 2

True

Question 3

Deposits of calcite built up in caves by dripping water are called dripstone or speleothems.

Answer 3

True

Question 4

Gravel has both high porosity and excellent permeability.

Question 5

An unconfined aquifer is recharged rapidly, whereas a confined aquifer recharges slowly.

Question 6

How fast groundwater flows depends, in part, on the permeability of the sediment through which it passes.

Question 7

Petrified wood develops when buried wood is saturated or replaced with calcite.

Question 8

When water is pumped from a well the water table is typically drawn down into a zone of depression.

Question 9

The amount of fresh water stored in oceans is many times greater than the amount of ground water.

Question 10

The capillary fringe is thicker in fine-grained sediments and thinner in coarse-grained sediments.

Question 11

Artesian wells are associated with confined aquifers.

Question 12

Groundwater is a major economic resource.

Question 13

Water in the upper part of the saturated zone tends to move downward following the slope of the water table.

Question 14

Compared to the flow of water in streams, most ground water moves relatively slowly.

Question 15

The saturated zone overlies the water table.

Question 16

The site selected for the disposal of high level radioactive waste is the ocean.

Question 17

Sandstones and gravels make the only aquifers; no other rocks are useful.

Question 18

The addition of new water to the saturated zone is called recharge.

Question 19

Gasoline leaked from gas station storage tanks is less dense than water and can rise to the top of the water in an aquifer.

Question 20

The rate of ground water flow tends to decrease with depth because sedimentary rock pores tend to be closed by increasing amounts of cement and the weight of the overlying rock.

Question 21

A(n) _________ aquifer is completely filled with water under pressure and is separated from the surface by an aquitard.

A) non-economic
B) non-productive
C) confined
D) blind or buried
E) underpressured

Question 22

An area with many sinkholes and caves is said to have ___ topography.

A) karst
B) decalcified
C) a subsidence-dominated
D) a wadi
E) cratered

Question 23

___ is the percentage of a rock or sediment that consists of void space.

A) Vugosity
B) Void index
C) Permeability
D) Porosity
E) Holiness

Question 24

A ________ is a place where water flows naturally from rocks onto the ground surface.

A) ground-water sink
B) well
C) spring
D) capillary
E) bore

Question 25

A(n) _______ is a body of saturated rock or sediment through which water can move easily.

A) sediment
B) evaporite
C) caprock
D) aquifer
E) aquiclude

Question 26

______ streams receive water from the saturated zone.

A) Spring loaded
B) Losing or influent
C) Gaining or effluent
D) Ephemeral
E) Persistent

Question 27

The upper surface of the saturated zone is called the __.

A) water table
B) hard pan
C) saturated lid
D) recharge zone
E) head level

Question 28

An _____ rock is one that does not allow water to flow through it easily.

A) atmospheric
B) indestructible
C) unfractured
D) unstable
E) impermeable

Question 29

A _____ is a deep, cylindrical hole that is dug or drilled into the ground to penetrate an aquifer within the saturated zone.

A) pump
B) well
C) deep aquifer
D) cone of depression
E) water hole

Question 30

________ refers to the ability of a rock to transmit fluids.

A) Porosity
B) Hydraulic head
C) Viscosity
D) Permeability
E) Void

Question 31

Shale is a common _____ because it retards the flow of ground water.

A) artesian aquifer
B) confined aquifer
C) aquifer
D) vadose rock
E) aquitard

Question 32

Most ________ and _________ are both porous and permeable.

A) mudstone; shale
B) siltstone; claystone
C) schist; quartzite
D) granite; gabbro
E) sandstone; conglomerate

Question 33

Heavy use of ground water can cause a region's water table to ____.

A) flow faster
B) disappear
C) increase in thickness
D) rise toward the ground surface
E) drop to deeper depths

Question 34

When water is pumped out of an unconfined aquifer through a well, a ___ often develops in the water table.

A) cone of depression
B) thin film of pollution
C) ground-water mound
D) piercement structure
E) deflation structure

Question 35

A deposit of loose sand may have a porosity of _____ percent.

A) 30-50
B) 20-30
C) less than 20
D) 40-50
E) more than 50

Question 36

Local lowering of the water table, called ____, tends to change the direction of groundwater flow by changing the slope of the water table.

A) drawdown
B) depressing
C) porosity
D) artesian
E) invasion

Question 37

The _____ is the zone above the water table.

A) replenishment zone
B) saturated zone
C) vadose zone
D) discharge zone
E) permeable zone

Question 38

___ is becoming a serious problem as demand for drinking water increases in coastal cities.

A) Pollution of the ocean's water
B) Decrease in seawater salinity
C) Development of fresh-water springs on the seabed
D) Salt-water intrusion into wells

Question 39

A _______ is a type of hot spring that erupts hot water and steam.

A) geyser
B) mud volcano
C) travertine
D) magma
E) lahar

Question 40

The amount of ground water is ____ that of all rivers and lakes combined.

A) equal to
B) very minor when compared to
C) a little less than
D) many times
E) of uncertain amount compared to

Question 41

Shales can have substantial porosity but have low _____.

A) cement
B) permeability
C) void space
D) pore space
E) conductivity

Question 42

Most caves are probably formed by ground water circulating ___ the water table.

A) at
B) below
C) above
D) with an uncertain relation to

Question 43

______ is a deposit of calcite that forms around hot springs.

A) Hematite
B) Quartz
C) Travertine
D) Stalactite
E) Sinter

Question 44

In unconfined aquifers water in shallow wells __.

A) will rise to the ground surface and flow freely at the surface
B) will rise just to the ground surface, but will not flow
C) will rise to the level of the water table
D) will not rise beyond the base of the well
E) There is not enough information to answer this question.

Question 45

The water table ______ in humid regions.

A) is kilometers deep
B) roughly parallels the land surface
C) reaches the ground surface at the top of hills
D) is at a fixed depth regardless of topography

Question 46

Gasoline leaking from an underground storage tank will __.

A) evaporate entirely to the atmosphere
B) sink past the water table to mix with ground water
C) infiltrate to the top of the water table, on which it will float
D) sink to the bottom of the saturated zone without mixing
E) remain trapped in the soils around the tank

Question 47

_____ form when slightly acidic ground water dissolves limestone along joints and bedding planes.

A) Pores
B) Caves
C) Flowstones
D) Concretions
E) Stalagmites

Question 48

In very dry climates such as deserts, rivers tend to be __.

A) gaining streams
B) subsequent streams
C) meandering streams
D) losing streams
E) consequent streams

Question 49

The unsaturated zone is __.

A) a zone of high biological activity located along the water table
B) the zone of capillary action adjacent to the water table
C) the zone of mixing at the water table
D) the zone above the water table
E) the zone at the ground surface that includes the soil profile

Question 50

A(n) ____ is a body of ground water separated from the main water table by a zone that is not saturated.

A) confined aquifer
B) perched water table
C) aquiclude
D) free aquifer
E) vadose zone

Question 51

___ states that the velocity of ground water equals permeability multiplied by hydraulic gradient.

A) Darcy's law
B) Einstein's equation
C) Newton's Law
D) Steno's principle

Question 52

In a(n) _____ aquifer water rises above the top of the aquifer when a drill penetrates it.

A) artesian
B) spring
C) erupting
D) dry

Question 53

____ water is water that contains relatively large amounts of dissolved calcium and magnesium.

A) Hard
B) Branch
C) Mineral
D) Soda
E) Soft

Question 54

Groundwater is important in the preservation of _____ which develops when porous buried wood is either filled in or replaced by inorganic silica carried in by ground water.

A) preserved wood
B) petrified wood
C) petrified material
D) preserved material

Question 55

The hydraulic head is defined as __.

A) the elevation of the water table
B) the pore fluid pressure
C) the velocity of water flow
D) the slope of the water table
E) elevation plus pore fluid pressure at a given point

Question 56

In parts of Texas and New Mexico the pumping of ground water has caused the water table of the Ogallala Reservoir to drop ____.

A) 30 centimeters
B) 1 meter
C) 3 meters
D) 10 meters
E) 30 meters

Question 57

____ are closed depressions found where land surfaces are underlain by limestone bedrock.

A) Cirque valleys
B) Craters
C) Kettle holes
D) Sinkholes
E) Inversions

Question 58

Given all other conditions are the same, ground water flows faster if __.

A) it is flowing through finer-grained materials
B) it is flowing in response to a greater hydraulic gradient
C) it is flowing through deeply buried material
D) it is colder
E) it is saturated with dissolved solids

Question 59

______ are icicle-like pendants of calcite hanging from cave ceilings.

A) Stalagmites
B) Flowstone
C) Straws
D) Stalactites
E) Concretions

Question 60

Heavily pumped wells near a coast can be contaminated by ____.

A) saltwater intrusion
B) radioactive waste
C) hard water
D) soft water
E) high iron water