# Shared Flashcard Set

## Details

Earths Cat Test 2
2nd test
38
Science
Undergraduate 1
11/08/2009

## Cards Return to Set Details

Term
 Elastic rebound theory
Definition
 earthquakes form elastically (unstrained), deforms, slips, repeats (leaves many scars)
Term
 Stress Drop
Definition
 sudden slip of a fault lowers stress and relaxes strain
Term
 Elastic Waves
Definition
 P waves and S waves (vibrations excited because youve changed state of stress)
Term
 P (primary) waves
Definition
 sound waves in rock, solids, and fluids (noise of rock on rock sliding) - propogation velocity ~6-13 km/sec
Term
 S waves (secondary)
Definition
 only in rock, not in air (shake ground) - propogation velocity ~ 2-7.3 km/sec
Term
 Love Waves
Definition
 (surface wave)-S waves reverberating in crust/upper mantle, shake ground horizontally, perpendicular to direction of propogation
Term
 Rayleigh Waves
Definition
 P&S waves interfere, shake the ground up and down/back and forth along direction of propogation
Term
 Results of Study of Seismic Waves:
Definition
 -locate earthquake sources, -compare size of events (magnitude, moment), -determine orientation of faults and sense of slip, -determine internal structure of the earth
Term
 Seismic Wave Amplitudes
Definition
 -proportional to amount of slip on fault, and to energy released in fault zone, -determine how big event was, -seismic wave spread from source as wave amplitude decreases
Term
 Measures of Earthquake size:
Definition
 -Intensity (Qualitative) : based on shaking damage, decreases with distance (all they could do pre 1900) -Magnitude (Quantitative/Empirical) : based on seismic wave amplitude -Seismic Moment (Quantitative/Theoretical) : based on actual fault slip
Term
 Primary Earthquake Hazards
Definition
 Fault Displacement and Ground Shaking
Term
 Secondary
Definition
 landslides, liquefaction, tsunamis, dam/highway/nuclear/chemical structure failiures, fire induced events
Term
 How to survive a tsunami:
Definition
 -go to high ground -get on a roof -climb a tree -if in water, grab on floating debris -Expect many waves
Term
 EQ Hazard Mitigation
Definition
 construction standards, civil preparation, land use planning, timely warning
Term
 Long-term forcasts (how frequently an area will be shaken):
Definition
 recurrence interval, seismic gaps/characteristic earthquakes, hazard maps (where you will have risks)
Term
 Short-term forecasts
Definition
 precursors, post/earthquake warning, Strain effects, Exotic Methods
Term
 Richter magnitude scale (1933)
Definition
 Charles Richter, richter magnitude = log(amplitude/wave period) + distance correlation
Term
 Greatest earthquake in recorded history
Definition
 1960 Chile, Mw=9.5
Term
 what happens whe a wave reaches a boundary in the earth
Definition
 reflaction, refraction, or conversion (p to s or s to p)
Term
 Products of volcanism:
Definition
 volcanic mountains -igneous rocks -dust -gas/water -trace gases: climate effects -geothermal energy -minerals/ores
Term
 present atmosphere (substances and percentages)
Definition
 79% nitrogen, 21% oxygen, traces of water, co2, ar, ne
Term
 geothermal energy (alternate energy sources)
Definition
 hydrothermal (water heated by sinking down in the crust and warming up by hot rocks) - 2x world supply of oil -hot dry rock - 6000x world supply of oil -magma reservoirs
Term
 where is diamond found
Definition
 under earth in carbon kimberlites
Term
 primary volcanic hazards
Definition
 explosions, lava, ash, nuees ardentes (gas and magma landslides), gas
Term
 secondary volcanic hazards
Definition
 landslides, lahards, tsunamis, agricultural disruption
Term
 Origin of volcanoes
Definition
 Ascent of Molten Rock (Magma) from deeper in Crust and Upper Mantle (earths core is magma)
Term
 Why is the earth hot inside?
Definition
 Primordial Gravitational Energy and Radioactive Decay of U, Th, K, Al
Term
 3 tectonic regions volcanoes occur in:
Definition
 Subduction Zones (island and continental arcs), Mid ocean ridges/rifts, Hotspots (plume of hot mantle rises)
Term
 Mt. Fujiyama
Definition
 Subduction Zone volcano, strato-volcano, deadly, erupted 1707
Term
 ARC volcanoes
Definition
 Near subduction zones: island arc or continental arcs
Term
 Andesite
Definition
 Most common rock type in arc volcanoes, relatively hi Si content, makes magma sticky,vicious lava piles up and make cones and bubbles with gas
Term
 Characteristics of Arc Volcanism
Definition
 explosive, gas traps and builds pressure, source magma rich in water and gas
Term
 Caldera Formation
Definition
 depression formed my collapse of magma chamber roof (fills with sediments and lava after explosion of magma)
Term
 Alfred Wegener
Definition
 1915-1930, developed notion of the continental riff, idea of super continent pangea
Term
 Abraham Orrelius
Definition
 1596 developed idea of pangea
Term
 Scuchert
Definition
 helped on idea of pangea
Term
 AA
Definition
 broken up, blocky, rough flow
Term
 Pahoehoe
Definition
 coherent, fluid, ropey or rippley surfaces
Supporting users have an ad free experience!