Geology
of California Robert
Lopez
Study
Questions 18: Earthquakes and Faults
1)
What
is Stress? What is strain?
2)
What
are the types of stress and what tectonic setting are they associated with?
3)
Does
the San Andreas Transform have all three types of stresses?
4)
Strain
is the result of what kind of changes in a rock?
5)
Where
is strain energy stored?
6)
What
are the three ways in which rocks strain as a result of stress?
7)
What
are the links between deformation, energy, and earthquakes?
8)
How
are earthquakes and faults related?
9)
Describe
briefly the elastic rebound theory.
10)
Describe
or sketch the relationship between the focus, epicenter, and surface rupture
for a dipping fault plane (fig. 2, attached).
Where do deep focus earthquakes occur, what is the maximum depth to
their focus, and what controls this limit?
What are typical focal depths of California earthquakes?
11)
What
is a fault scarp?
12)
How
are active faults officially defined?
13)
What
are the differences among P, S, and surface waves?
14)
What
is the evidence that the outer core is liquid?
15)
Sketch
a simple seismogram tracing showing the there types of waves.
16)
What
is a seismograph?
17)
How
the epicenter of an earthquake can be located?
18)
What
specifically controls the Richter magnitude?
Be able to compare the amplitudes of seismic waves yielding different
Richter magnitudes (e.g., compare amplitudes of magnitude 4 and 6 quakes).
19)
What
is the principal problem with the Richter magnitude? (“The Richter magnitude does not directly measure the overall
mechanical power of the seismic source, just as the strongest wind gust is not
a reliable measure of the overall force of a wind storm.” Bolt, 1993, p. 59).
20)
What
is MW, why is it “better” than the Ricther magnitude, and what three
factors are considered in its calculation?
Compare ML and MW for the 1989 Loma Prieta and 1906 San Francisco
earthquakes (see Harden, Table 13-1, p. 298).
21)
A
change in magnitude of one unit corresponds to an energy change of what (also
see Fig. 3, attached)?
22)
How
does “earthquake intensity” differ from magnitude, how is it measured, and what
factors influence it (Harden, Table 13-2)?
23)
Outline the five effects of earthquakes
below.
24)
What
are Tsunamis? What is the origin of the word?
25)
What
type of earthquakes usually result in Tsunamis?