Physical
Geology Fall
2000
Study
Questions 17: San Andreas Fault System
1)
What
is the San Andreas Fault System? On a
map, be able to identify four San Francisco Bay Area faults that make up the
San Andreas fault system in the Bay area.
2)
What
type of fault is the San Andreas?
3)
What
is creep and how does if differ from a long-term slip rate?
4)
What
are the two reasons why understanding the long-term slip rate is important?
5)
Name
two Bay Area faults that creep. What
part of the San Andreas fault proper is a creeping segment. (page 381)
6)
What
is the average rate of movement on the San Andreas Fault over the past 1800
years? (page 360)
7)
What
is the rate of plate motion between the Pacific and North American plates in
the past 3 to 4 million years? (page 361)
8)
What
makes up the difference between the two rated calculated in the two problems
above?
9)
What
is a seismic gap, and what is the seismic gap theory?
10)
What
is the most dangerous fault in the San Francisco Bay Area?
11)
Why
is the fault referred to in question above considered to be the most dangerous?
12)
Where
is Parkfield and why has there been so much interest among geologists
concerning Parkfield? What is the average time between magnitude 6.0 quakes on
this segment of the fault before the most recent quake? When did the last quake
occur at Parkfield and what was the magnitude?
13)
What
are three sources of seismic waves?
14)
What
is a restraining bend in a strike slip fault (sketch it)?
15)
Where
is the Big Bend in the San Andreas fault, and how does it cause compression?
(p. 384)
16)
What
geologic province is the result of the Big Bend compression?
17)
What
is the significance of Pallet Creek? (page 386)
18)
On
what type of faults have three recent Big Bend area earthquakes (San Fernando
quake of 1971, Whittier Narrows quake of 1987, Northridge quake of 1994)
occurred on? (see page 391)
19)
How
old is the San Andreas? (see page 364)
20)
What
geologic features, units do geologists use as criteria for 315 km of movement
on the San Andreas in the past 23.5 million years? (p. 361-363)
21)
Approximately
how many km of rupture patch occurred during the Loma Prieta earthquake?
22)
What
type of movement occurred on the San Andreas Fault?
23)
Where
is the Carrizo Plain? What are sag ponds, offset streams, compressional ridges,
and linear valleys. (p. 365 and p. 382)
24)
How
much slip occurred in the Carrizon Plain as a result of the 1857 Fort Tejon
earthquake? (page 384)