Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
91 Cards in this Set
- Front
- Back
|
Continental drift theory came from.. |
Alfred Wegener (1912) |
|
|
What are the 4 things that proved continental drift? |
1. Continents fit together
2. Fossils are found on separate sides of continents (matching animals/plants found) 3. Correlation of mountains with nearly identical rocks and structures 4. Glacial features of the same age restore to a tight polar distribution |
|
|
Why did it take 50 years for Alfred Wegener's theory to be accepted? |
No accepted mechanism for moving continents through oceans
Arguments about timing of orogenies He was a meteorologist working in geology |
|
|
What dredged rocks are found on the ocean floor? |
only basalt, gabbro, and serpentinite - no continental materials
|
|
|
Where is the youngest and oldest crust found? |
youngest crust in the center and outwards is the oldest crust
|
|
|
What is the theory of seafloor spreading? |
The theory of seafloor spreading suggests that molten rock breaks through split at the top of the ridge
The rock then spreads out in both directions from the ridge as if it were on two huge conveyor belts |
|
|
When does the theory of Plate Tectonics begin? |
Begins in 1960s It was stated that Earth’s crust is broken up into several “plates” that move due to convection in mantle The core heats up and pushes the mantle up (mantle upwelling) and then it cools and comes back down |
|
|
What are the plates made of? |
Entirely oceanic crust and continental crust Little mix of both |
|
|
What are Divergent Plate Boundries? |
Plates that are moving away from each other and form new crust Also known as rift zones, spreading centers, and ocean ridges The rising magma pushes the ocean crust away from each other |
|
|
Where is the mid atlantic ridge? What kind of plate boundry is it? |
Iceland. Divergent Plate Boundry. |
|
|
What kind of plate boundry is the gulf of california (baja)? |
Divergent Plate Boundry |
|
|
What kind of plate boundry is the east african rift valley? |
Divergent Plate Boundry |
|
|
What are convergent plate boundaries? |
Plates that come together |
|
|
Subduction bones |
Ocean crust destroyed |
|
|
Ocean-ocean convergent boundary
|
boundaries coming in together
ocean crust is melting back into the mantle |
|
|
Volcanic Island Arc
|
partially melt and then rises to surface to cool and becomes rock again forming islands
(Fiji, Japan) |
|
|
Ocean-continental convergent boundary
|
oceanic crust is being subducted underneath continental crust
continental crust is less dense and bigger (Cascade Mts, Andes) |
|
|
Continent - continent Convergent Boundary
|
continental crust collides w/ continental crust, forming highly folded mts
Himalayas - modern day Alps - modern day Appalachian Mts - ancient day NO volcanic activity where two subduction zones converge |
|
|
Exception to volcanic activity where two subduction zones converge |
Hotspots -> intra-plate volcanism
Hawaii Long valley (ancient) yellowstone |
|
|
Transform plate boundry |
no destruction or creation of crust
instead crust is being displaced (moved) majority of TPB are found on the ocean floor (San Andreas fault) |
|
|
Groundwater |
Is water stored in pore spaces between grains of soil and sediment, as well as narrow joints and fractures in bedrock |
|
|
What is the largest reservoir freshwater that is readily available to humans? |
Groundwater |
|
|
How does the water enter the system at the ground surface? |
Through recharge. |
|
|
How does the water leave the system? |
Through discharge. |
|
|
Where does recharge and discharge occur? |
Recharge at higher elevations and discharge at lower elevations. |
|
|
Porosity |
amount (as %) of open space in rock |
|
|
Permeability |
The ability of water flow through a rock influence by how well the pores are connected |
|
|
Aquifer |
Highly premeable layer that allows flow of water |
|
|
What is an aquitard/aquiclude? |
Impermeable layer that restricts flow |
|
|
Unconfined aquifer |
no confining layer (aquitard) above restrict flow of water |
|
|
Confined aquifer |
Aquitards above and/or below aquifer restrict flow of water |
|
|
What is the water table? |
It is the unconfined aquifer and potentionmetric surface is a confined aquifer |
|
|
Staturated zone |
Pores are completely filled with water |
|
|
What are unsaturated zone? |
pores are empty or partially filled with water |
|
|
Water line |
Dividing the line between where you do and don't have water
|
|
|
Artesian wells |
well drilled into a confined aquifer where the water will rise up due to release of pressure |
|
|
Poteniometric surface |
Water table for a confined aquifer |
|
|
When the water table lowers, the cone of depression around the pumping well (water table is lowest right around the wel). True or false? |
True. |
|
|
Land subsidence |
As confined aquifers and aquitards lose water, they compress and shrink, causing the land surface to sink (New oreleans, Mexcio City, Venice, and more cities all over the world are subsided.) |
|
|
Features from groundwater are.. |
Hotsprings/geysers Natural springs Kaurst topographny |
|
|
Geysers and hot springs require.. |
Source of heat (magma), fractures system to transmit, large supply of groundwater |
|
|
Springs |
form when water table intersects the land surfave form faults intersecting aquifer or aquifer comes in contact with aquiclude |
|
|
Karst Topography |
forms from dissolution of carbonate rocks (limestone/marble) by acidic rainwater (groundwater) |
|
|
Current groundwater search |
GRACE and Monitoring Groundwater The Gravity Recovery and Climate Experiment (GRACE) tracks changes in the amount of stored groundwater by observing changes in the strength of gravity around the globe |
|
|
Weakening gravity = ? |
Decreasing groundwater
|
|
|
Strengthening gravity = ? |
Increasing groundwater |
|
|
What are the strategies to mitigate groundwater depletion issues? |
Conservation and water recycling |
|
|
What are some examples of sources of contaminates? |
Leaking septic tanks, highway salt, fertilizers/pesticides, landfills, and fracking |
|
|
Hydraulic fracturing |
Method used to remove oil from shale |
|
|
Convention well |
oil and gas are accessible using vertical |
|
|
Unconventional well |
Oil and gas are accessible using horizontal drilling and hydraullic fracturing |
|
|
Conservation |
Using more efficient irrigation systems Growing more water efficient crops |
|
|
Water Recycling |
Purifying used wastewater and injecting it back into the aquifer |
|
|
Divergent Plate Boundary Volcanoes |
Shield volcanoes: gentle, broad, slopes (Sierra Grande in New Mexico) Mostly basalt |
|
|
Types of basalt lava |
Aa: jagged and angular - lava is cooler and has lost lots of gas Pahoehoe: ropey and more fluid |
|
|
Convergent Plate Boundry Volcanoes |
Strato-Volcano (also called Composite Volcanoes) Plug dome (type of strato) Caldera (forms from strato) |
|
|
Strato Volcano |
Sleep slopes, alternating layers of pyroclastic material and lava flows, lava cools to form andesite and/or rhyolite Mount Fuji (composite or strato) |
|
|
Plug dome |
Form when the lava too thick to flow builds up on itself (forms a plug) and therefore seals the vent Mt St Helens |
|
|
Caldera |
a crater that is >1km in diameter forms when summit collapses into magma chamber after large eruption Crater Lake (Oregon) |
|
|
Hot spots |
Plume magma from mantle comes up through crust and forms a volcanic structure Hawaii (shield) Yellowstone (caldera) |
|
|
Haleakala, Muai |
Ten eruptions in last 1,000 (last eruptions as late as 1790) |
|
|
Kilauea Summit |
Worlds most active volcano |
|
|
Yellowstone(super volcano) |
Yellowstone hotspot (beneath continental crust) volcanic smug (yellowstone) |
|
|
Flood basalts |
Mantle plume transport magma to crust and numerous fractures and fissures bring lava to surface |
|
|
Cinders are built from? |
Lava fragments (pyroclastic material) |
|
|
Fumaroles |
Where volcanic gases escape (steam CO2, SO2) |
|
|
Viscosity |
Measure of liquids resistance to flow |
|
|
Factors that affect Viscosity |
Temperature Chemical Composition and Chemical Composition (Increase T, decreases Viscosity) |
|
|
The more Si content the more Viscosity. What is the content of Basalt, Andesite/Rhyolite |
Basalt - low Andesite/Rhyolite - low |
|
|
Lahars |
Volcanic mudflows Nevada Del Ruiz (Andes Mts) |
|
|
Pyroclastic flows |
Pyroclast: pulverized rock, lava and glass fragments explosively ejected, range in size from very fine dust and ash to bombs Flow: is ground-hugging avalanche of pyroclastic that moves as fast as 100m/hr with T > 800c |
|
|
Magnitude |
Related to amount of energy released |
|
|
Moment Magnitude Scale (1979) |
Quantity that combines surface area of rupture zone and amount of displacement with a measure of rock strength |
|
|
Intensity (qualitative measure) |
Measure of earthquakes effect on humans and structures |
|
|
Factors that influence intensity of earthquake |
Distance (Shaking less intense further from epicenter) Depth focus |
|
|
Length of fault rupture |
Longer fault rupture = longer earthquake |
|
|
Sediment conditions |
soft sediment or rock - shake more intensely than solid rock |
|
|
Liquefaction |
Process that occurs when water separates from sediment and moves to the surface when the water saturated materials are violently shaken |
|
|
Tsunamis |
Seismic sea waves generated by earthquakes |
|
|
Alquist-Priolo Act 1973 |
States that structures for human occupancy cannot be set of trace of fault and must be set back 50ft (100ft for larger faults) |
|
|
Field Act 1933 |
Banned construction of unreinforced masonry buildings (brick, adobe) retrofitted school buildings to withstand greater lateral forces |
|
|
Hypocenter (focus) |
Actual location of the earthquake at depth (where the earthquake happened) |
|
|
Epicenter |
Location on the surface of the earth above the hypocenter (point of reference) |
|
|
Hanging wall |
top block of a fault (where light would hang from) |
|
|
Footwall |
bottom block of a fault (where you would stand) |
|
|
Elastic rebound theory |
as plates move, rocks are "bending" to accomdofate the increase in pressure |
|
|
Seismic waves |
result of energy released from a fault |
|
|
What are body waves? |
P-waves (fastest, travel through liquids solids and gas) and S-waves (slower, travel only through solids) |
|
|
Surface waves are |
Love waves (particle motion perpendicular to the direction of wave propagation - zig zag - fastest of surface wave) and rayleigh waves (equivalent to water waves except that particle motion of water waves is prograde/forward - slower) |
|
|
Seismographs |
Instruments that record vertical and horizontal movement associated with an earthquake |
|
|
San Andreas Fault |
locked sections = no movement (seismic gaps)
creeping sections = slow movement along fault between earthquake events Northern and Southern locked 1906 San Fran was the last creep |
