Tectonic Geomorphology

1
Tectonic Geomorphology

• Introduction to the San Andreas Fault System
• Simple model for earthquake cycle elementary
  dislocation theory

http//whipple_arrowsmith598.asu.edu/
2
(No Transcript)
3
(No Transcript)
4
Areas of contrasting behavior along the San
Andreas Fault (from Allen, 1968)
Carrizo Plain
5
Long and short term deformation along the San
Andreas Fault

• Examples of issues of spatial and temporal scale
  of interest. Also indicates rate of deformation.

6
1906 M7.8 San Francisco EarthquakeBeginning of
modern earthquake science
7
(No Transcript)
8
1906 earthquake surface rupture. 8 fence offset
above http//mnw.eas.slu.edu/Earthquake_Center/19
06EQ/1906thumb.html And http//quake.wr.usgs.gov/i
nfo/1906/images/fenceoffset_big.html
9
Reids elastic rebound hypothesis
http//quake.wr.usgs.gov/info/1906/reid.html
10
http//www.matter.org.uk/matscicdrom/manual/di.htm
l
Edge dislocation
Screw dislocation
Dislocation simple idealization of displacement
discontinuity in continuous body
11
Idealization of brittle crust with embedded
strike slip fault (Thatcher, 1990)
12
Strike-slip parallel displacements from simple
screw dislocation model (Thatcher, 1990)
13
1906 coseismic displacements
14
Best fit depth 7000 m
15
Buried screw dislocation to interpret steady
interseismic motion along central SAF From swath
of SCEC crustal motion model (derived from
geodetic measurements of benchmark motionGPS
older trilateration, etc.). Compare rate with
Wallace Creek 3700 yr slip rate.
16
Young, et al., 2001
17
(No Transcript)
18
(No Transcript)