# Shared Flashcard Set

## Details

Test #3
Earthquakes
33
Geology
04/01/2014

Term
 Earthquake
Definition
 shaking of the ground caused, most often, by the sudden release of energy stored inelastically-strained rocks (Elastic Rebound Theory)
Term
 Focus
Definition
 the place within the Earth where energy is released
Term
 Epicenter
Definition
 the point on the Earth’s surface directly above the focus
Term
 Seismic Waves
Definition
 vibrational energy waves that travel outward in all directions from thefocus.
Term
 Seismograph
Definition
 machine used to measure seismic waves
Term
 Seismogram
Definition
 data produce by a seismograph
Term
 Surface Waves
Definition
 1. travel along earth's surface2.slowest seismic wave at 2.5 km (1.5 miles) per second3.responsible for much earthquake damage
Term
 Body Waves
Definition
 seismic waves that travel through the interior of the Earth
Term
 Types of Body Waves
Definition
 1. S-Waves2. P-Waves
Term
 Primary (P) Waves
Definition
 1.compressional wave.2.fastest seismic waves 6 km (4 miles) per second.3.transmitted through solids and liquids
Term
 Secondary (S) Waves
Definition
 1.shear wave2.slower at 3.5 km (2 miles) per second3.transmitted only through solids
Term
 Shear Wave
Definition
 rocks move up and down perpendicular to the direction of the wave
Term
 Compressional Wave
Definition
 alternating compression and expansion of the rock in the direction of the wave
Term
 Locating an earthquake's epicenter
Definition
 1.Distance of a seismograph from the epicenter is determined by the difference in arrival times of P and S waves.2.Data from 3 seismic stations is used to triangulate the location of the epicenter
Term
 Measuring earthquakes
Definition
 1.Mercalli Scale2.Richter Scale3.Moment Magnitude Scale
Term
 Mercalli Scale
Definition
 based on damage to buildings
Term
 Richter Scale
Definition
 1.Based on amplitudes (wave heights) of the largest seismic waves2.Logarithmic Scale
Term
 Logarithmic Scale
Definition
 an increase of 1 on the scale:=10 fold increase in intensity and a=30 fold increase in energy released
Term
 Moment Magnitude Scale
Definition
 a measure of earthquake strength base on:1.rupture size2.rock properties3.amount of ground displacement along the fault
Term
 Earthquake Zones
Definition
 1.Most earthquakes occur along plate boundaries.2.Depth of earthquake foci is related to type of plate boundary3.Intraplate earthquakes
Term
 Intraplate earthquakes
Definition
 shallow (< 50 km). Mechanism is not well understood
Term
 Plate Boundaries
Definition
 1.Oceanic divergent boundaries2.Continental rifts, collision zones and transforms3.Subduction zones
Term
 Subduction zones
Definition
 1.deep (up to 700 km).2.Wadati-Benioff zones
Term
Definition
 earthquakes that occur in the subducting slab
Term
 Continental rifts, collision zones and transforms
Definition
 shallow to moderate (< 80km)
Term
 Oceanic divergent boundaries
Definition
 shallow (< 20 km)
Term
 Earthquake Destruction
Definition
 1.Ground Motion2.Liquifaction3.Landslides4.Fire5.Seismic Sea Waves (Tsunamis)
Term
 Ground Motion
Definition
 destruction varies:1.Type of ground surface–soft sediments amplify vibrations more than solid rock2.Structural design of buildings
Term
 Earthquake Prediction
Definition
 1. Short-term Predictions2. Long-term Predictions
Term
 Short-term Predictions
Definition
 1.Monitoring of phenomena such as: ground uplift and subsidence, strain in rocks2.no reliable method
Term
 Long-term Predictions
Definition
 1.attempts to establish a recurrence interval 2.Seismic gaps
Term
 Seismic Gaps
Definition
 areas known to be under strain that have not produced earthquakes
Term
 Recurrence Interval
Definition
 based on: a.historically dated eventsb.dating of fault and quake activity
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