Geol-111 Groundwater

Front 1

From what 2 sources does the heat that causes geysers originate?

Back 1

1) magma
2) geothermal gradient

Front 2

Logs or trees that have turned into stone:

Back 2

Petrified wood

Front 3

What causes a rise in the Earth’s temperature w/ increasing depth?

Back 3

Geothermal gradient

Front 4

What happened to the Leaning Tower of Pisa?

Back 4

There was an overuse of groundwater which caused subsidence and thus made the tower lean.

Front 5

A lowering of the water table around a pumping well:

Back 5

Cone of depression

Front 6

What is one of the most famous sinkholes in the U.S.?

Back 6

Winter Park, FL (“Porsches”)

Front 7

Groundwater does not exist in the ____ ____ because of suction force.

Back 7

Unsaturated zone

Front 8

What 2 features are often found in areas w/ karst topography?

Back 8

1) caves
2) sinkholes

Front 9

Stream in which the bottom of the streambed lies above the water table:

Back 9

Losing stream

Front 10

What is so special about the hot springs in Hot Springs National Park?

Back 10

1) Very hot (140 degrees F)
2) The springs have a fairly low dissolved mineral content
3) Brand new microorganism discovered

Front 11

Water-producing unit that easily transmits water (has high hydraulic conductivity):

Back 11

Aquifer

Front 12

What industry has major problems w/ groundwater contamination?

Back 12

Agricultural industry

Front 13

Water table that cannot pump groundwater:

Back 13

Perched water table

Front 14

Which earth materials have low levels of hydraulic conductivity?

Back 14

Rocks:
-silt
-clay
-granite
-mudrock

Front 15

What is the second largest use of the world’s groundwater?

Back 15

Industry and power supply

Front 16

Unit with very low hydraulic conductivity which slows down the movement of groundwater:

Back 16

Confining bed

Front 17

How much porosity is adequate for producing groundwater?

Back 17

Reasonable porosity (10-40%)

Front 18

The lowering of the land surface:

Back 18

Subsidence

Front 19

In a recreation of the Darcy experiment, water is flowing through a tube filled with gravel. The cross-sectional area of the tube is 100 cm2. The discharge flowing from the tube is 500 cm3/sec. The hydraulic head is measured in two, thin tubes. The hydraulic head in tube #1 is 20 cm; the hydraulic head in tube #2 is 10 cm. If the tubes are 100 cm apart, what is the hydraulic conductivity of the gravel?

Back 19

Q = K x A x [H1-H2]/L
500 = K x 100 x [20-10]/100
500 = K x 100 x [10]/100
500 = K x 100 x 0.10
500 = 10K
10 10
50 cm/sec = K

Front 20

Which aquifers have the greatest risk of contamination and why?

Back 20

Unconfined aquifers b/c they are very shallow and are not protected by confining beds.

Front 21

What is the average annual income for Louisiana refinery workers?

Back 21

$47,000

Front 22

Streams that only have water after it rains:

Back 22

Losing streams

Front 23

Energy from hot springs and geysers:

Back 23

Geothermal energy

Front 24

What is LA’s primary source of water?

Back 24

Surface water

Front 25

Why did most of the gas stations in the U.S. have a “Renaissance”?

Back 25

Their underground soil tanks were leaking which and causing groundwater contamination; they all had to be changed.

Front 26

A well in a confined aquifer:

Back 26

Artesian well

Front 27

Areas in which some, but not all of the pores are filled w/ water:

Back 27

Unsaturated zone

Front 28

How much of Earth’s water is surface water?

Back 28

0.4%

Front 29

What rock makes the best aquifer?

Back 29

Cavernous limestone

Front 30

What is the typical porosity of sandstone and limestone?

Back 30

10-30%

Front 31

What are the advantages/disadvantages of geothermal energy?

Back 31

ADVANTAGES:
-very clean energy source
DISADVANTAGES:
-limited only to places w/ springs/geysers
-very expensive

Front 32

Shallow aquifer that is close to the surface:

Back 32

Unconfined aquifer

Front 33

Forms when the water table intersects the surface:

Back 33

Spring

Front 34

A measure of the heighth of water:

Back 34

Hydraulic head

Front 35

We use more ____ water than ____ water.

Back 35

Surface water, ground water (surface water is easier to get)

Front 36

Excluding the ice in glaciers, if all fresh water on Earth was liquid, how much of it would be in groundwater?

Back 36

94%

Front 37

The percentage of earth material that is void (empty) space:

Back 37

Porosity

Front 38

Subsurface water that moves very slowly through the void spaces of earth material:

Back 38

Groundwater

Front 39

From what source do the hot springs/geysers in Yellowstone National Park come from?

Back 39

Heat that comes from the magma below the surface

Front 40

The boundary that separates the unsaturated zone from the saturated zone:

Back 40

Water table

Front 41

Aquifer that is often used for private wells:

Back 41

Unconfined aquifer

Front 42

Which earth materials have high levels of hydraulic conductivity?

Back 42

Sediments:
-gravel
-sand
-sandstone
-limestone

Front 43

Circular, collapsed depressions that form over underground openings:

Back 43

Sinkholes

Front 44

What is the biggest use of the world’s groundwater?

Back 44

Agricultural irrigation

Front 45

Area in which all of the pores are filled w/ water:

Back 45

Saturated zone

Front 46

What earth material contains the highest level of porosity?

Back 46

Clay (50-70%)

Front 47

What is the average annual income in LA?

Back 47

$20,000

Front 48

Springs in which the water temperature is hotter than the human body:

Back 48

Hot springs

Front 49

Where is the bottom of the streambed located in a gaining stream?

Back 49

Below the water table

Front 50

Aquifer that is often used in public or municipal locations:

Back 50

Confined aquifer

Front 51

What is the typical porosity of granite and mudrock?

Back 51

0-10%

Front 52

To produce groundwater, earth materials need to have what 2 characteristics?

Back 52

1) Reasonable porosity (10-40%)
2) High hydraulic conductivity

Front 53

What areas are often affected by salt water intrusion?

Back 53

Coastal areas that use a lot of groundwater (FL)

Front 54

What is Ruston’s primary source of water?

Back 54

Groundwater

Front 55

What is the third largest use of the world’s groundwater?

Back 55

Human use

Front 56

Where is the perched water table located?

Back 56

In the unsaturated zone

Front 57

Stream in which the bottom of the streambed lies below the water table:

Back 57

Gaining stream

Front 58

Where and how do most caves form?

Back 58

Most form just below the water table by the dissolution of limestone

Front 59

What is a major problem associated w/ unconfined aquifers?

Back 59

Groundwater contamination

Front 60

How do you calculate Darcy’s Law?

Back 60

Q = K x A x [H1-H2]/L
Q = discharge
K = hydraulic conductivity
A = cross-sectional area
[H1-H2] = change in hydraulic head
L = length

Front 61

What makes up the top of the unconfined aquifer?

Back 61

Water table

Front 62

What is one of the main problems with unconfined aquifers?

Back 62

Subsidence

Front 63

How of Earth’s water is groundwater?

Back 63

0.6%

Front 64

Water that replenishes the ground water system:

Back 64

Recharge (primarily rain – 5%)

Front 65

The ability of earth material to transmit water:

Back 65

Hydraulic conductivity

Front 66

Hot springs that eject hot water and steam?

Back 66

Geysers

Front 67

The unit from which Ruston gets its drinking water:

Back 67

Sparta aquifer

Front 68

The water level of a well in a confined aquifer:

Back 68

Potentiometric surface

Front 69

What is the typical porosity of silt?

Back 69

30-50%

Front 70

The dominant force that moves groundwater in the ____ ____ is gravity.

Back 70

Saturated zone

Front 71

Occurs when less and less water can be pumped out of the ground water system:

Back 71

Depletion

Front 72

What are the features associated w/ hot groundwater known as?

Back 72

Geothermal activity

Front 73

Cave formations:

Back 73

Speleothems

Front 74

Where are most of the United States’ hot springs/geysers located?

Back 74

Yellowstone National Park

Front 75

The top of this aquifer is the water table:

Back 75

Unconfined aquifer

Front 76

What is the only igneous rock that makes good aquifers?

Back 76

Scoria (vesicular) basalt

Front 77

Petrified wood is formed when logs turn into ____.

Back 77

Quartz

Front 78

Why can’t you pump groundwater from a perched water table?

Back 78

1) It has no pattern
2) It is too small

Front 79

Aquifer that is sandwiched between confining beds:

Back 79

Confined aquifer

Front 80

To what level will a well fill when drilled into the ground?

Back 80

The water table

Front 81

A landscape that is produced when groundwater interacts w/ limestone:

Back 81

Karst topography

Front 82

In a recreation of the Darcy experiment, water is flowing through a tube filled with sand. The cross-sectional area of the tube is 100 cm2. The hydraulic conductivity of the sand is 1 cm/sec. The hydraulic head is measured in two thin tubes. The hydraulic head in tube #1 is 20 cm; the hydraulic head in tube #2 is 10 cm. The tubes are 10 cm apart. What is the volume of water discharging from the tube?

Back 82

Q = K x A x [H1-H2]/L
Q = 1 x 100 x [20-10]/10
Q = 1 x 100 x [10]/10
Q = 1 x 100 x 1
Q = 100 cm3/sec

Front 83

Where is the bottom of the streambed located in a losing stream?

Back 83

Above the water table

Front 84

From what source does the hot springs in Hot Springs National Park come from?

Back 84

The geothermal gradient

Front 85

Which aquifers have problems with subsidence?

Back 85

Unconfined aquifers

Front 86

Where do layers of low hydraulic conductivity trap infiltrating groundwater?

Back 86

Perched water table

Front 87

What often affects coastal areas that use a lot of groundwater?

Back 87

Salt water intrusion