Geology 1403 Exam 3
questions and answers
2025
What is an earthquake - answer seismic waves or vibrations caused by the sudden
release of energy, usually as a result of the displacement of rocks along faults
What causes earthquakes - answer energy released at plate boundary
interactions
What are the locations of earthquakes - answer primarily along plate boundaries
-80% Circum-Pacific or Ring of Fire
-15% Mediterranean-Asiatic belt
examples: Japan, Chili & Haiti
-5% within plate interiors
examples: Missouri & small quakes in U.S., Australia
Examples of plate margin interactions - answer Africa, New Zealand, San Andres
Mountain Ranges, CA
What is elastic rebound - answer the mechanism by which energy is released
during earthquakes.
ex. 1906 San Francisco earthquake displaced a fence 15'
What is the Focus - answer hypocenter or the point within the Earth where
fracturing or rupturing begins is first released at this point
seismic waves move from the focus
What is the Epicenter - answer the point on Earth's surface directly above the
focus
, What are the categories and focal depths of earthquakes - answer -Shallow focus
is less than 70km at the crust and upper mantle
-intermediate-focus-is 70-300km at the astenosphere
-deep-focus is greater than 300km at the asthenosphere and possible lower
mantle (only felt by seismic recordings)
What is a seismic wave - answer energy released at the focus of an earthquake
radiates outward in all direction from the focus. This energy travels in the form of
seismic or vibrating waves
What are the types of seismic waves - answer -Body waves travel through the
solid body of the earth
Primary or P and Secondary or S Waves
-Surface waves travel along the ground surface and are slower
Rayleigh or R and Love or L Waves
What are P Primary Waves - answer -Fast
-Compressional or push-pull (slinky)
-move material back and forth in the direction of the wave
-travel through solid, liquid, gas or all mediums
What are S Secondary Waves - answer -slower than P-waves
-shear
-move material perpendicular to the direction of the wave producing shear stress
-travel through solids only
S's--slow, shear and solids
What are the Surface Waves - answer -R waves and L waves
What do surface waves do - answer generally produce a rolling or swaying motion,
similar to standing on a boat
What type of wave is used to locate an earthquake - answer Body waves
questions and answers
2025
What is an earthquake - answer seismic waves or vibrations caused by the sudden
release of energy, usually as a result of the displacement of rocks along faults
What causes earthquakes - answer energy released at plate boundary
interactions
What are the locations of earthquakes - answer primarily along plate boundaries
-80% Circum-Pacific or Ring of Fire
-15% Mediterranean-Asiatic belt
examples: Japan, Chili & Haiti
-5% within plate interiors
examples: Missouri & small quakes in U.S., Australia
Examples of plate margin interactions - answer Africa, New Zealand, San Andres
Mountain Ranges, CA
What is elastic rebound - answer the mechanism by which energy is released
during earthquakes.
ex. 1906 San Francisco earthquake displaced a fence 15'
What is the Focus - answer hypocenter or the point within the Earth where
fracturing or rupturing begins is first released at this point
seismic waves move from the focus
What is the Epicenter - answer the point on Earth's surface directly above the
focus
, What are the categories and focal depths of earthquakes - answer -Shallow focus
is less than 70km at the crust and upper mantle
-intermediate-focus-is 70-300km at the astenosphere
-deep-focus is greater than 300km at the asthenosphere and possible lower
mantle (only felt by seismic recordings)
What is a seismic wave - answer energy released at the focus of an earthquake
radiates outward in all direction from the focus. This energy travels in the form of
seismic or vibrating waves
What are the types of seismic waves - answer -Body waves travel through the
solid body of the earth
Primary or P and Secondary or S Waves
-Surface waves travel along the ground surface and are slower
Rayleigh or R and Love or L Waves
What are P Primary Waves - answer -Fast
-Compressional or push-pull (slinky)
-move material back and forth in the direction of the wave
-travel through solid, liquid, gas or all mediums
What are S Secondary Waves - answer -slower than P-waves
-shear
-move material perpendicular to the direction of the wave producing shear stress
-travel through solids only
S's--slow, shear and solids
What are the Surface Waves - answer -R waves and L waves
What do surface waves do - answer generally produce a rolling or swaying motion,
similar to standing on a boat
What type of wave is used to locate an earthquake - answer Body waves
