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Geology Final
Groundwater and Coasts
74
Geology
Undergraduate 3
02/22/2013

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Cards

Term
Out of all the Earth's water, what percent is ocean water?
Definition
97%
Term
Percentage of Earth's water of glaciers?
Definition
2%
Term
Percentage of Earth's water of "everything else?"
Definition
0.6% groundwater (irrigation)
0.4% surface water (human resources)
Term
Porosity?
Definition
percentage of Earth material(rock, sediment); "space between material;" allows water space.
Term
Typical porosites?
Definition
sediment and rock
Term
Sediment(porosite)?
Definition
gravel and sand(20-40%), silt(35-55%), clay(50-70%).
Term
Rock(porosite)?
Definition
sandstone and limestone(10-30%), granite and mudrock(0-5%).
Term
Hydrolic Conductivity?
Definition
ability of Earth material to transmit water; permeable, key in water production; higher the better=easier flow; connectedness of pore spaces.
Term
High hydrolic conductivity?
Definition
gravel, sand, sandstone, limestone
Term
Low hydrolic conductivity?
Definition
silt, clay, granite, mudrock
Term
Groundwater system?
Definition
unsaturated zone, saturated zone, water table.
Term
Unsaturated Zone?
Definition
water and air in pore spaces; partially saturated; NOT groundwater but plants use it.
Term
Saturated Zone?
Definition
all water in pore spaces; groundwater.
Term
Water Table?
Definition
separates the unsaturated zone and the saturated zone.
Term
Confining bed?
Definition
hard to transmit water; low hydrolic conductivity materials.
Term
Aquifers?
Definition
unit that stores/transmits water; high hydrolic conductivity materials. Two types: unconfined and confined
Term
Unconfined aquifer?
Definition
closest to the surface; the top is the water table; "drinking from a straw" results in water decreasing.
Term
Confined aquifer?
Definition
found between confining beds; "squeezing a sponge, water drop by drop." more consistent with water extraction.
Term
Artesian well?
Definition
found in unconfined aquifers.
Term
Potentiometric surface?
Definition
well found in confined aquifers; high in pressure; water shoots up based on pressure.
Term
Geology of Louisiana?
Definition
Ruston-Sparta aquifer (600-800ft deep). Confining units:cook mountain and cane river.
Term
Perched water table?
Definition
produced by low hydrolic conductivity layer in unsaturated zone; mini aquifer.
Term
Gaining/Losing streams?
Definition
based on location of stream bed. Below water table is gaining stream and above the water table is losing stream.
Term
Recharge?
Definition
water that replenishes the groundwater system. Usually rainfall(only 5-10% infiltrates ground).
Term
Spring?
Definition
forms when the water table intersects the ground surface.
Term
Problems?
Definition
depletion, subsidence, contamination, salt water intrusion.
Term
Depletion?
Definition
results when amount of pumping is greater than the amount of recharge.
Term
Cone of depression?
Definition
forms in confined/unconfined aquifers; lowering of water table at the pumping of a well.
Term
Subsidence?
Definition
lowering of land surface; water holds grains apart and keeps pores open. EX. sand, gravel...Leaning Tower of Pisa, San Wakim Valley.
Term
Contamination?
Definition
pollution from agriculture, gasoline,septic tanks, etc.
Term
Salt water intrusion?
Definition
coastal regions that use groundwater; wells break into salt water from ocean and mixes with fresh water. EX. Florida
Term
Karst Topography?
Definition
interaction of groundwater and limestone; caves and sinkholes.
Term
Caves?
Definition
form just below water table, water drains,then continues to drip in slowly, reacts with cave air and forms cave formations.
Term
Speleothems?
Definition
cave formations;EX. stalacite, stalagmite, limestone columns.
Term
Sinkholes?
Definition
"sinking" ground above a cave or cavern; ground collapses into the cave; usually circular. EX. Winter Park, Florida.
Term
Petrified wood?
Definition
wood that has been turned to stone. Fallen trees become buried under Earth materials, silica(dissolved quartz) in groundwater flows through the tree.
Term
Geothermal activity?
Definition
hot springs, geysers, geothermal energy.
Term
Hot springs?
Definition
when water is hotter than body temperature; temperatures vary; EX. Mammoth Hot Springs in Yellowstone.
Term
Geysers?
Definition
subset of hot springs; pressure from hot water underground causes water to erupt.
Term
Geothermal energy?
Definition
heat and electricity produced by using the internal heat of the Earth; clean energy, not as cost effective, Iceland.
Term
Heat comes from?
Definition
magma(ex. Yellowstone) and geothermal gradient: increase of Earth's temperature with depth (ex. Hot Springs, Arkansas).
Term
Coasts?
Definition
highly populated; 60% of US population.
Term
Continental margins?
Definition
part of the continent that extends into the water. Three parts: shelf, slope, and rise.
Term
Shelf?
Definition
maximum water depth is 500 m (1500 ft), broad, and relatively flat surface; near shoreline.
Term
Slope?
Definition
maximum water depth is 4 km (13,000 ft). Not very steep and extends from the shelf.
Term
Rise?
Definition
maximum water depth 4.5 km (13,500 ft). Almost completely flat; extends to deep ocean floor/abyssal plane.
Term
Submarine canyons?
Definition
canyons on outer edge of shelf.
Term
Turbidity currents?
Definition
cloudy mass of sediments and rushing water.
Term
Abyssal fans?
Definition
accumulation of deposited sediments under water; aka turbidities; gradient beds.
Term
Waves?
Definition
wind blowing across the water causes friction that results in waves; move in circular motion;higher waves by shoreline.
Term
Waves depend on?
Definition
strength of wind and fetch: distance that wind blows over open water.
Term
Wave crest?
Definition
distance between successive waves; top of wave; wave length.
Term
Wave trough?
Definition
bottom of wave.
Term
Wavelength?
Definition
distance between waves; crest to crest or trough to trough.
Term
Wave height?
Definition
vertical distance between wave and trough.
Term
Wave refraction?
Definition
the bending of waves as they reach the shore; Two types: headland and embayment. Shoreline eventually straightens.
Term
Headland?
Definition
erosion; close to water; high energy; "crest"
Term
Embayment?
Definition
depostion; low energy; "troughs"
Term
Currents?
Definition
the moving flow of water in a stream; well-defined. Two types: longshore and rip.
Term
Longshore currents?
Definition
narrow current between surf zone and shoreline; moves parallel to the beach.
Term
Rip current?
Definition
strong, localized seaward flow of water perpendicular to the beach.
Term
Types of Coasts?
Definition
rocky and sandy.
Term
Rocky coast?
Definition
bedrock (sea cliff) rises directly from the sea; high erosion from wave activity;
Term
Wave cut bench?
Definition
platform of rock.
Term
Sea arch?
Definition
arch of land protruding into the sea and connected to mainland.
Term
Sea stacks?
Definition
isolated tower of land offshore that is remnants of the sea cliff.
Term
Sandy coast?
Definition
beaches; passive margin.
Term
Spit?
Definition
hooked, curved sandbar; beach stretches out into open water.
Term
Baymouth bar?
Definition
sandspit that grows across the opening of a bay.
Term
Barrier island?
Definition
offshore sand bar that rises above the mean high-water, level forming an island.
Term
Coastal issues?
Definition
Contemporary sea level changes (global warming) and beach destruction.
Term
Groin?
Definition
concrete or stone wall built perpendicular to shoreline in order to prevent beach drift from removing sand.
Term
Jetty?
Definition
man-made wall that protects the entrance to a harbor; built on side of river to keep channel open.
Term
Breakwater?
Definition
offshore wall built parallel or at an angle to the beach, that prevents the full force of the waves from reaching a harbor.
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