Fall 2009

Geol/Geop 558

Mechanics of Earthquakes and Faulting

Instructors:

Gary Axen, gaxen@ees.nmt.edu, x5178

Susan Bilek, sbilek@nmt.edu, x6510, office hours Wednesdays 9:30 am - noon

Glenn Spinelli, spinelli@ees.nmt.edu, x6512

 

Time and Place: Thursdays, 6:30-9:30 pm, MSEC 202

Required Text: The Mechanics of Earthquakes and Faulting, by Christopher Scholz

Schedule:

Date

Topic

Reading

Proposal deadline

8/27

Intro to course; Organization; Proposal discussion

 

 

9/3

Basics of stress, strain, constitutive relations (GA)

- J. Byerlee, 1978, Friction of Rocks, Pageoph, 116, 615-626.


- Scholz sec. 1.1-1.2

 

9/10

Rocks as materials, crustal stress regimes (GA)

- Scholz sec. 2.1-2.2

 

9/17

Crustal strength models

 

- Scholz, 3.1


- Townend and Zoback, 2000, How faults keep the crust strong, Geology, 28 (5), 399-402 (Moyer)


- Sibson, 1994, An assessment of field evidence for Byerlee friction: Pageoph 142, 645-662 (Moyer)


- Brace & Kohlstedt, 1980, Limits on lithospheric stress imposed by laboratory experiments, JGR, 85, 6248-6252

 

9/24

San Andreas fault overview; weak vs. strong faults

- Scholz, 2000, Evidence for a strong San Andreas Fault, Geol., 28 (2), 163-166. (Whitney)


- Townend and Zoback, 2004, Regional stress near the San Andreas fault in central and southern California, Geophys. Res. Letters, 31 (L15S11). (Myers)


- Lachenbruch and McGarr; 1990, Stress and heat flow; in Wallace, The San Andreas fault system, CA: USGS Prof. Paper 1515; 261-277. (Myers)


- Hardebeck and Michael, 2004, Stress orientations at intermediate angles to the San Andreas Fault, California, J. Geophys. Res. 109, doi: 10.1029/2004JB003239. (Maraj)

 
10/1

Strong vs. weak faults

 

- Rice, 1992, Fault stress states, pore pressure distributions, and the weakness of the San Andreas Fault, in Fault Mechanics and Transport Properties of Rocks, p. 475-503. (Michelsen)


- Faulkner et al., 2006, Slip on weak faults by the rotation of regional stress in the fracture damage zone, Nature, 444, 922-925. (Michelsen)

 

10/8

Low Angle Normal Faults (GA)

- Axen and Selverstone, 1994, Stress state and fluid-pressure level along the Whipple detachment fault, California, Geology, 22, 835-838.

- Wernicke, 1995, Low-angle normal faults and seismicity: A review, J. Geophys. Res., 100, 20159-20174.

- Axen, 2007, Research focus: Significance of large-displacement, low-angle normal faults, Geology, 35, 287-288.

Topic selection

10/15

Fault rocks and gouge

 

- Di Toro et al., 2006, Natural and experimental evidence of melt lubrication of faults during earthquakes, Science, 311, 647-649. (Cozzens)


- Cowan, 1999, Do faults preserve a record of seismic slip? A field geologists opinion, Journal of Structural Geology, 21, 995-1001. (Maraj)


- Spray, 1992, A physical basis for the frictional melting of some rock-forming minerals; Tectonophys., 204, 205-221. (Khalsa)

Outline & reference list

10/22

Rate-state friction, pore fluid effects on stability (GS)

- Scholz sec. 1.3, 2.3, 2.4, 3.4

- Fulton and Saffer, 2009, Potential role of mantle-derived fluids in weakening the San Andreas Fault

 
10/29

Critical wedge theory

 

- Davis et al., 1983.  Mechanics of fold-and-thrust belts and accretionary wedges, J. Geophys. Res., 88, 1153-1172. (Cozzens)


- Saffer and Bekins, 2002, Hydrologic controls on the morphology and mechanics of accretionary wedges, Geology, 30 (3), 271-274. (Spinelli)

 
11/5

Earthquake mechanics & statistics (SB)

- Kanamori and Brodsky, 2004, The physics of earthquakes, Reports on Progress in Physics, 67, 1429-1496.

 

11/12

Earthquake dynamics, rupture models (SB)

- Kanamori and Brodsky, 2004, The physics of earthquakes, Reports on Progress in Physics, 67, 1429-1496.


- Scholz sec. 4.1, 4.2

 

11/19

Earthquake statistics;
Stress drop

 

- Abercrombie, 1995, Earthquake source scaling relationships from -1 to 5 ML using seismograms recorded at 2.5 km depth, J. Geophys. Res., 100,  24015-24036. (Ruhl)


- Ide and Beroza, 2001, Does apparent stress vary with earthquake size?, Geophys. Res. Lett. 28, 3349-3352. (Khalsa)

Submit draft for peer review

11/26 (TBA)

Fault geometry and earthquakes

 

- Stein, 1999, The role of stress transfer in earthquake occurrence, Nature, 402, 605-609. (El-Hariri)


- Wesnousky, 2006, Predicting the endpoints of earthquake ruptures, Nature 444, 358-360. (Whitney)


- Robinson et al., 2006, Earthquake rupture stalled by a subducting fracture zone, Science, 312, 1203-1205. (El-Hariri)

Return reviewed proposal to peer

12/3

Slow earthquakes;
Episodic tremor and slip

 

- Schwartz and Rokosky, 2007, Slow slip events and seismic tremor at circum-Pacific subduction zones, Reviews of Geophysics, 2006RG000208. (Bilek)

- Nadeau and Guilhem, 2009, Nonvolcanic tremor evolution and the San Simeon and Parkfield, California, earthquakes, Science, 325, 191-193. (Ruhl)

Final proposal

12/10

Proposal presentations (1-2 fig., 5 min. presentations)