Quiz Study Guide Section 2.2 EARTHQUAKES AND SEISMIC WAVES
Key Concepts
 How does the energy of an earthquake travel through Earth?

What are the scales used to measure the strength of an earthquake?

How do scientists locate the epicenter of an earthquake?
Important Terms
 earthquake- the shaking and trembling that results from the movement of rock beneath
Earth’s surface
 focus- the point beneath the Earth’s surface where rock that is under stress breaks and
triggers an earthquake
 epicenter- the point on the Earth’s surface directly above the focus
 magnitude- the number that geologists assign to an earthquake based on the earthquake’s
size
3 Types of Seismic Waves
Type of Seismic
Wave
P wave
(Primary waves)
Arrival Time
Motion
first, fastest
compress and expand like an
accordion
Amount of
Damage
minimal (not a
lot)
S wave
(Secondary waves)
surface wave
second, medium
speed
last, slowest
side to side & up and down
moderate
causes ground to move like an
ocean wave
severe
3 Types of Scales



Mercalli Scale- rates earthquakes according to the level of damage at a given place- I to
XII (Roman numerals)
Richter Scale- rating of an earthquake’s magnitude based on the size of the earthquake’s
seismic waves- 1 to 10
Moment Magnitude Scale- rating system that estimates the total energy released by an
earthquake-1 to 10