More on Seismic Gaps

1
More on Seismic Gaps

• Locked Fault segments (Los Angeles big bend and
  Garlock Fault San Francisco fault splays)

2
Fig. 4-2, p.67
3
Fig. 3-21, p.46
4
Fig. 4-28, p.79
5
Fig. 4-29, p.80
6
Fig. 4-16, p.75
7
Creeping Segments

• Example Calaveras Fault

8
Fig. 4-23, p.77
9
Dangerous Locked Segments

• San Francisco, 1906

10
Fig. 4-28, p.79
11
Fig. 4-24, p.78
12
Fig. 4-25, p.78
13
Fig. 4-26, p.78
14
Fig. 4-27, p.78
15
Dangerous Locked Segments

• The Big Bend, 1857 (near Los Angeles)

16
Fig. 4-16, p.75
17
Effect of Locking?

• Blind Thrusts (already discussed) Example
  Northridge, 1994

18
Fig. 4.28
Northridge Earthquake (Revisited)
19
Fig. 4-30, p.81
20
Fig. 4-36, p.83
21
Fig. 4-32, p.82
22
Fig. 4-33, p.82
23
Fig. 4-34, p.83
24
Fig. 4-35, p.83
25
Fig. 4-37, p.84
26
More on Seismic Gaps

• Focal migration
• Example Anatolia Fault, Turkey

27
Fig. 4-38, p.86
28
Fig. 4-47, p.90
29
(No Transcript)
30
(No Transcript)
31
Fig. 4-39, p.86
32
Fig. 4-4, p.68
33
An annoying normal fault

• Wasatch Fault, Salt Lake City, Utah

34
Fig. 4-51, p.91
35
Fig. 4-52, p.92
36
Fig. 4-53, p.92
37
Fig. 4-54, p.92
38
Fig. 4-55, p.93
39
Front Range / Denver Basin normal faults
Fig. 4-10, p.71
40
Another annoying (paleo) normal fault?

• Charleston, SC 1886
• East Coast Fault System may be reactivation of
  normal faults associated with initial rifting of
  Atlantic Ocean, 200 m.y.

41
Fig. 4-60, p.96
42
New Madrid, 1811 and 1812

• John James Audubon describes Rayleigh waves
• Audubon, John James (1897). "Audubon and His
  Journals"
• Journal from western KY "...at that instant all
  the shurbs and trees began to move from their
  roots, the ground rose and fell in successive
  furrows, like the ruffled waters of a lake...
• http//www.showme.net/fkeller/quake/lib/eyewitnes
  s1.htm

43
Fig. 4-13, p.72
44
Fig. 4-57, p.94
45
Mississippi Embayment

• Possibly an aulucogen from opening of Atlantic
• Separates Oauchitas from Smokies