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87 Cards in this Set

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  • Back
From what 2 sources does the heat that causes geysers originate?
1) magma
2) geothermal gradient
Logs or trees that have turned into stone:
Petrified wood
What causes a rise in the Earth’s temperature w/ increasing depth?
Geothermal gradient
What happened to the Leaning Tower of Pisa?
There was an overuse of groundwater which caused subsidence and thus made the tower lean.
A lowering of the water table around a pumping well:
Cone of depression
What is one of the most famous sinkholes in the U.S.?
Winter Park, FL (“Porsches”)
Groundwater does not exist in the ____ ____ because of suction force.
Unsaturated zone
What 2 features are often found in areas w/ karst topography?
1) caves
2) sinkholes
Stream in which the bottom of the streambed lies above the water table:
Losing stream
What is so special about the hot springs in Hot Springs National Park?
1) Very hot (140 degrees F)
2) The springs have a fairly low dissolved mineral content
3) Brand new microorganism discovered
Water-producing unit that easily transmits water (has high hydraulic conductivity):
Aquifer
What industry has major problems w/ groundwater contamination?
Agricultural industry
Water table that cannot pump groundwater:
Perched water table
Which earth materials have low levels of hydraulic conductivity?
Rocks:
-silt
-clay
-granite
-mudrock
What is the second largest use of the world’s groundwater?
Industry and power supply
Unit with very low hydraulic conductivity which slows down the movement of groundwater:
Confining bed
How much porosity is adequate for producing groundwater?
Reasonable porosity (10-40%)
The lowering of the land surface:
Subsidence
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?
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
Which aquifers have the greatest risk of contamination and why?
Unconfined aquifers b/c they are very shallow and are not protected by confining beds.
What is the average annual income for Louisiana refinery workers?
$47,000
Streams that only have water after it rains:
Losing streams
Energy from hot springs and geysers:
Geothermal energy
What is LA’s primary source of water?
Surface water
Why did most of the gas stations in the U.S. have a “Renaissance”?
Their underground soil tanks were leaking which and causing groundwater contamination; they all had to be changed.
A well in a confined aquifer:
Artesian well
Areas in which some, but not all of the pores are filled w/ water:
Unsaturated zone
How much of Earth’s water is surface water?
0.4%
What rock makes the best aquifer?
Cavernous limestone
What is the typical porosity of sandstone and limestone?
10-30%
What are the advantages/disadvantages of geothermal energy?
ADVANTAGES:
-very clean energy source
DISADVANTAGES:
-limited only to places w/ springs/geysers
-very expensive
Shallow aquifer that is close to the surface:
Unconfined aquifer
Forms when the water table intersects the surface:
Spring
A measure of the heighth of water:
Hydraulic head
We use more ____ water than ____ water.
Surface water, ground water (surface water is easier to get)
Excluding the ice in glaciers, if all fresh water on Earth was liquid, how much of it would be in groundwater?
94%
The percentage of earth material that is void (empty) space:
Porosity
Subsurface water that moves very slowly through the void spaces of earth material:
Groundwater
From what source do the hot springs/geysers in Yellowstone National Park come from?
Heat that comes from the magma below the surface
The boundary that separates the unsaturated zone from the saturated zone:
Water table
Aquifer that is often used for private wells:
Unconfined aquifer
Which earth materials have high levels of hydraulic conductivity?
Sediments:
-gravel
-sand
-sandstone
-limestone
Circular, collapsed depressions that form over underground openings:
Sinkholes
What is the biggest use of the world’s groundwater?
Agricultural irrigation
Area in which all of the pores are filled w/ water:
Saturated zone
What earth material contains the highest level of porosity?
Clay (50-70%)
What is the average annual income in LA?
$20,000
Springs in which the water temperature is hotter than the human body:
Hot springs
Where is the bottom of the streambed located in a gaining stream?
Below the water table
Aquifer that is often used in public or municipal locations:
Confined aquifer
What is the typical porosity of granite and mudrock?
0-10%
To produce groundwater, earth materials need to have what 2 characteristics?
1) Reasonable porosity (10-40%)
2) High hydraulic conductivity
What areas are often affected by salt water intrusion?
Coastal areas that use a lot of groundwater (FL)
What is Ruston’s primary source of water?
Groundwater
What is the third largest use of the world’s groundwater?
Human use
Where is the perched water table located?
In the unsaturated zone
Stream in which the bottom of the streambed lies below the water table:
Gaining stream
Where and how do most caves form?
Most form just below the water table by the dissolution of limestone
What is a major problem associated w/ unconfined aquifers?
Groundwater contamination
How do you calculate Darcy’s Law?
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
What makes up the top of the unconfined aquifer?
Water table
What is one of the main problems with unconfined aquifers?
Subsidence
How of Earth’s water is groundwater?
0.6%
Water that replenishes the ground water system:
Recharge (primarily rain – 5%)
The ability of earth material to transmit water:
Hydraulic conductivity
Hot springs that eject hot water and steam?
Geysers
The unit from which Ruston gets its drinking water:
Sparta aquifer
The water level of a well in a confined aquifer:
Potentiometric surface
What is the typical porosity of silt?
30-50%
The dominant force that moves groundwater in the ____ ____ is gravity.
Saturated zone
Occurs when less and less water can be pumped out of the ground water system:
Depletion
What are the features associated w/ hot groundwater known as?
Geothermal activity
Cave formations:
Speleothems
Where are most of the United States’ hot springs/geysers located?
Yellowstone National Park
The top of this aquifer is the water table:
Unconfined aquifer
What is the only igneous rock that makes good aquifers?
Scoria (vesicular) basalt
Petrified wood is formed when logs turn into ____.
Quartz
Why can’t you pump groundwater from a perched water table?
1) It has no pattern
2) It is too small
Aquifer that is sandwiched between confining beds:
Confined aquifer
To what level will a well fill when drilled into the ground?
The water table
A landscape that is produced when groundwater interacts w/ limestone:
Karst topography
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?
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
Where is the bottom of the streambed located in a losing stream?
Above the water table
From what source does the hot springs in Hot Springs National Park come from?
The geothermal gradient
Which aquifers have problems with subsidence?
Unconfined aquifers
Where do layers of low hydraulic conductivity trap infiltrating groundwater?
Perched water table
What often affects coastal areas that use a lot of groundwater?
Salt water intrusion