How can we help?

You can also find more resources in our Help Center.

36 terms

Geology: Earthquakes (Third Exam)

STUDY
PLAY
focus
The _____ is the source of the Earthquake.
waves
Energy is released in the form of _____.
faults
Earthquakes are usually associated with large fractures in the Earth's crust called ______
H.F. Reid
Who first described the mechanism for earthquakes?
Elastic rebound
Rocks on both sides of an existing fault are deformed by tectonic forces, rocks bend and store elastic energy are both components of what?
rebound, focus
Elastic _____ says that slippage at the weakest point (the _____) is an earthquake mechanism
aftershock
adjustments that follow a major earthquake often generate smaller earthquakes that are called
foreshocks
small earthquakes, called __________, often precede a major earthquake by days
fault creep
faults that exhibit slow, gradual displacement are said to have
stick-slip motion
What is the process called by which segments of faults store energy for periods of time to rupture in great earthquakes?
seismology
What is the study of earthquake waves?
seismographs
What instruments record seismic waves?
true
True or False? Seismographs work by recording the movement of the Earth in relation to a stationary mass of a rotating drum or magnetic tape.
surface waves
What kind of seismic waves travel along the outer part of the Earth?
surface waves
What kind of waves have these characteristics? Complex motion, cause great damage, greatest amplitude, slowest velocity, waves that have the greatest periods, and are often referred to as L waves
Body waves
What kind of seismic wave has two types?
Primary and Secondary
What are the two types of body waves?
primary waves
What kind of wave has push-pull ( compress and expand) motion?
primary
What kind of wave travels through solids, liquids, and gases?
volume
Primary waves change the ______ of rocks, which respond elastically.
Primary
Which kind of body wave travels faster? (1.7x faster)
secondary
What kind of body waves have a "shake" motion at right angles to their direction of travel.
secondary
Which kind of body waves travel only through solids?
greater
Secondary waves have a _______ amplitude than P waves.
shape
Secondary waves change the _____ of rocks through which they travel. Rocks respond elastically to this.
epicenter
The location on the surface directly above the focus
velocities
Epicenter is located using the difference in ________ of P and S waves.
three
How many stations are needed to locate an epicenter?
70
A shallow earthquake's foci is shallow if it is anywhere between the surface and __ kilometers
intensity
a measure of the degree of earthquake shaking at a given locale based on the amount of damage
magnitude
estimates the amount of energy released at the source of the earthquake
buildings
The modified Marcalli Intensity Scale was developed using California _______ as its standard
Richter
The _______ scale was based of the amplitude of the largest seismic wave recorded, accounts for the decrease in wave amplitude with increased distance.
2
Magnitudes lass than _.0 are not felt by humans
liquefaction
Unconsolidated materials saturated with water turn into a mobile fluid is known as ___________ of the ground
seiches
What is it called when the rhythmic sloshing of water in lakes/reservoirs cause waves that can weaken reservoir and cause damage?