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69 Cards in this Set
- Front
- Back
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Groundwater percentages
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50% of Texas supply, 40% of U.S. supply
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What does the water table seperate?
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Saturated, vadose (aerated) zones
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Groundwater can be supply...
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streams (gaining streams) or fed by streams (losing streams)
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What do aquifers transmit?
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useful quantities of groundwater
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Description of the flow of groundwater...
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from high to low water table elevations
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Groundwater typically seeps at what rate?
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10 meters per year
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Where does groundwater naturally emerge?
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springs and geysers
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Major problem associated with with pumping groundwater...
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causes cone of depression in water table that results in... 1. supply well contamination 2. subsidence 3. saltwater intrusion 4. rising energy costs
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Two other groundwater problems include...
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sinkholes and contamination
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Glacier
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Thick mass of ice, originates on land from accumulation, compaction of snow, shows evidence of movement.
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Where is the Surf Zone
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Region of breaking waves
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Where is the Swash Zone
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Sloping front of beach, the uprush and downrush of water.
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What is Wave Refraction
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The bending of wave fronts as they approach shoreline.
Causes greatest erosion at headlands, deposits sediment in adjacent bays. |
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Shorelines are shaped by?
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Wave energy
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What is long-shore drift?
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The net movement of sand parallel to a shoreline. Waves approach shoreline diagonally, but drain straight back down the beach. This moves sand in a zig-zag pattern
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Sources of Sand
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Rivers, local corals, or cliffs
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What are some erosional shore line features?
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Sea arches - water tunnels through cliffs; caves on opposite sides of headland unite.
Sea Stack - what's left when an arch collapses Wave Cut Cliffs |
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What are some depositional shoreline features?
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Spits - thin ridges of sand that project from the headland into the mouth of an adjacent bay. If it crosses the bay it forms a baymouth bar.
Barrier Islands - low ridges of sand parallel to coast, off shore. |
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What is a groin?
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A linear structure perpendicular ro shoreline, used to maintain or widen beaches that are losing sand.
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What is a jetty?
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A pair of linear structures perpendicular to shoreline, used to keep entrances to rivers open.
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Valley Glacier (alpine)
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follow mountain valleys
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Continental Glacier (ice sheets)
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Flow out in all directions
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Rate of glacial movement...
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typically a few centimeters a day
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Plastic Flow
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below about 50 meters
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Basal Slips
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Entire ice mass slips along ground due to meltwater within glacier.
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Two types of glacial erosion
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plucking and abrasion
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Till
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Deposited directly by glacier, poorly sorted, "erratics".
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Stratified Drift
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sand, gravel laid down by glacial meltwater, well sorted.
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Deserts
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dry places not necessarily hot.
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Where are deserts common?
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in subtropics and mid latitudes
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Wind transport in deserts...
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bedload (sand) and suspended load (silt)
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Deflation
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lifting and erosion of loose material results in lowering of land surface, desert pavement (veneer coarser particles)
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Abrasion
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Cutting and polishing exposed rock surfaces (ventifacts)
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Sculpting
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yardangs
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Wind Deposition
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sand deposits (dunes) from bedload, wind shadow effect.
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What is a breakwater?
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A linear structure parallel to the shoreline, used to protect ships and property.
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What is a sea wall?
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Located behind the beach, is used to lessen the force of waves that hit it, and prevent flooding.
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What is beach nourishment?
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If there is muddy sand it would kill the coral.
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The sea level is rising!
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about 3mm/y, caused by global warming, flatter land is more susceptible.
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Instrument used to map the Ocean Floor
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Echo-sounder
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What is the continental margin?
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Passive: Shelf, slope, rise.
Shelf - flooded extension of continent Slope - boundary between continental and oceanic crust, submarine canyons, turbidite deposits. Rise - gradual descent to deep ocean. Active: little or no shelf, steep slope,no rise. |
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What is the ocean basin floor?
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flat, abyssal plains.
steep volcanic peaks (seamounts) form near ocean ridges. Called guyots if they have flat tops. |
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What is an ocean trench?
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long and narrow, deepest part of the ocean, sites where moving plates were destroyed and plunged into the mantle.
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What is the mid-ocean ridge?
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-elevated, extensively faulting, with many volcanic structures
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Sea Floor Sediment:
Terrigeneous |
mineral grains weathered from continental rocks and transported to ocean. With sand near the shore and mud further out
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Five desert landforms...
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1. dunes
2. alluvial fans 3. Bajada 4. intermittent streams 5. playa lakes |
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Desertification
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Expansion of desert-like conditions into surrounding areas. ex. plowing, clearing vegetation, livestock
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Seismic Vibrations
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pipes, wells, roads, buildings, houses, dams
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Tsunamis
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Seismic sea wave
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Fires
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severed gas, electrical lines
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Way of earthquake control
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use of fluids
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Deepest drill hole in the earth...
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17 kilometers deep.
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Crust
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- continental:(granitic) 35 km, density= 2.8 g/cc
- Oceanic:(basaltic) 5 km, density= 3.0 g/cc - Moho= base of crust (denser rocks beneath) |
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Mantle
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- 2900 km thick
- 80% earth's volume - Density= 3.3 to 5.5 g/cc |
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Outer Core
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- 2300 km thick
- liquid, metallic - iron, nickel, others |
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Inner Core
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- radius is 1200 km
- solid |
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Sea Floor Sediment:
Biogeneous |
shells, skeletons of marine organisms
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Sea Floor Sediment:
Hydrogeneous |
sediment with minerals that crystallized directly from water
ex: limestone, gypsum, halite |
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What is an Earthquake?
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Vibration of earth's surface caused by rapid energy release.
usually occurs when deformed rocks suddenly break along a fault. |
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What is elastic rebound?
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As plates on opposite sides of a fault are subjected to force and shift, they accumulate energy and slowly deform until their internal strength is exceeded. At that time, a sudden movement occurs along the fault, releasing the accumulated energy, and the rocks snap back to their original undeformed shape
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What is the focus?
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The point at which the slip initiates, pulses of energy (seismic waves) radiate in all directions from this point.
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What is the epicenter?
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Projection of focus to the surface.
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Seismic Waves
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Surface
P (primary): compressional, oscillate in direction of wave transmission through both solids and liquids. Fastest S (secondary): shear, oscillate at right angles to direction of wave transmission, not through liquids. Slower |
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How to locate the Epicenter
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use the difference in arrival times between first P and S waves.
Need at least 3 stations |
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Earthquake intensity:
effects of quake at a particular location depend on... |
-strength of the earthquake
-distance from the epicenter -population -rocks and soil -building materials |
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what is an earthquake's magnitude?
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-strength (amt of energy released)
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What is the Richter Scale?
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-measures max. amplitude of ground shaking recorded on seismic record (seismogram)
One increase in unit = 10 times more ground shaking, and 32 times more energy. |
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Cone of Depression
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in water table forms around well, means it takes more energy to pump deeper water. This is bad because of sinkholes, draw in pollution, water flows from high to low.
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Aquifers are porous and permeable.
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true
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