Geologic Constraints on the Physics of Earthquake Rupture


J.S. Chester and F.M. Chester
(Center for Tectonophysics, Department of Geology and Geophysics,
Texas A&M University, College Station TX)

NSF Tectonics EAR-0510892: July 1, 2005 to May 31, 2009
NSF EarthScope EAR-0454525: May 12, 2005 to May 11, 2007
SCEC Subcontract from USC EAR-0106924: 2003-2005

 

Project Scope

We are using structural observations of active and exhumed faults of the San Andreas system to provide new constraints on the earthquake energy budget.   In particular, work focuses on characterizing the physical processes of earthquake slip, and quantifying the specific fracture energy of rupture, which is defined as the energy consumed by the formation of the rupture surface and loss of frictional strength.   Constraining the specific fracture energy is important to modeling the dynamics of earthquake rupture propagation. The research involves detailed field mapping, sampling, and optical and electron microscopy and microprobe study of several key surface exposures of the active San Andreas fault and exhumed faults of the San Andreas system to quantify particle size distributions and fracture surface area within the faults, particularly focusing on nanoscale particles.   In addition, the mechanisms of particle size reduction, healing and particle growth in seismic faults are being determined.   The results contribute to developing synoptic models that describe the 3-D structure of seismogenic fault zones and attempt to relate structural/petrologic characteristics to the mechanical parameters important for earthquake rupture nucleation, propagation, and arrest.   The project is contributing to broad research programs and initiatives of national interest, such as National Earthquake Hazard Reduction Program (NEHRP), the Southern California Earthquake Center (SCEC), and the San Andreas Fault Observatory at Depth (SAFOD-EarthScope), and the scientific benefits of this work is maximized by coordinating with other researchers in the broader scientific community. The research provides education-through-research opportunities for both undergraduate and graduate students, and addresses the fundamental physics of earthquakes, which ultimately may contribute to reduction of earthquake hazards and improved mitigation.

Method to calculate fracture surface area of the Punchbowl fault (from Chester et al., 2005).

 

 
Investigation of the Punchbowl fault ultracataclasite from macroscopic to microscopic scale.
 

Masters Theses and Doctoral Dissertations

  • Teresa Sabato Ceraldi (PhD Geology, in progress). SAFOD Research.
  • Hiroko Kitajima (PhD Geology, in progress). SCEC Research.
  • Rafael Almeida (MS Geology, in progress). SAFOD Research.
  • Leslie Neal (MS Geology, 2002). Structure and petrology of the Kern Canyon fault, California: A deeply exhumed strike-slip fault (abstract). USGS NERHP 01HQGR0056
  • Jennifer Wilson (MS Geology, 1999). Microfracture fabric of the Punchbowl fault zone, San Andreas system, California (abstract). USGS NERHP Research 1434-HQ-96-GR-02709

Publications

  • Chester, J. S., Chester, F. M., Kronenberg, A. K., Fracture surface energy of the Punchbowl Fault, San Andreas system, Nature, 437, 133-135, 2005. pdf
  • Chester, F. M., Chester, J. S ., Kirschner, D. L., Schulz, S. E., Evans, J. P., Structure of large-displacement strike-slip fault zones in the brittle continental crust.   In: Karner, Gary D., Taylor, Brian, Driscoll, Neal W., Kohlstedt, David L. (eds.), Rheology and Deformation in the Lithosphere at Continental Margins.   Columbia University Press, New York, MARGINS Theoretical and Experimental Earth Science Series 1, 223-260, 2004. pdf
  • Wilson, J., Chester, J.S., and Chester, F.M., Microfracture analysis of fault growth and wear processes, Punchbowl Fault, San Andreas System, California, Journal of Structural Geology, v. 25, no. 11, p. 1855-1873, 2003. pdf

SCEC Nuggets

  • Chester, J. S., H. Kitajima, T. Shimamoto, and F.M. Chester, Characterization of microstructures relevant to earthquake mechanics in natural and experimental slip surfaces, 2005. pdf
  • Chester, J. S., F. M. Chester, and A. K. Kronenberg, Fracture surface energy of the Punchbowl fault, CA, 2004. pdf
  • Chester, J. S., A. K. Kronenberg, F. M. Chester, and R. N. Guillemette, Characterization of natural slip surfaces relevant to earthquake mechanics, 2003. pdf

Field Guides to San Andreas System fault exposures, southern California.

  • Chester, F. M., and Chester, J. S., A Journey to the Center of the Punchbowl Fault, California, SCEC FARM Workshop, 2005. pdf (2.5 M)
  • Chester, J. S., and Chester, F. M., A Picturesque Path Through Pulverized Rock along the San Andreas Fault Near Wrightwood California, California, SCEC FARM Workshop, 2005. pdf (1 M)

Abstracts and Oral Presentations

  • Almeida, R., Chester, J., Chester, F., Waller, T. J., and Kirschner, D., Moore, D., Lithology and structure of SAFOD Phase I core samples, EOS Trans. AGU, T21A-0454, 86(52), 2005.
  • Kirschner, D.L., Evans, J., Chester, J., Chester, F., Solum, J., Moore, D., Elemental and stable isotope chemistry of cuttings and core samples from SAFOD drill hole, EOS Trans. AGU, T21A-0452, 86(52), 2005.
  • Chester, J. S., Kitajima, H., Shimamoto, T., and Chester, F. M., Dynamic weakening of ultracataclasite during rotary shear at seismic slip rates, EOS Trans. AGU, T21B-0472, 86(52), 2005.
  • Chester, J. S., Kronenberg, A. K., Chester, F. M., Guillemette, R. N, Characterization of natural slip surfaces relevant to earthquake mechanics, EOS Trans. AGU, 84(46), 2003.
  • Neal, L A., Chester, J. S., Chester, F. M., Wintsch, R. P., Internal structure of the Kern Canyon fault, California: A deeply exhumed strike-slip fault, EOS Trans. AGU, 81, p. F1145, 2000.
Some of this material is based upon work supported by the National Science Foundation under Grant No. EAR-0510892 and EAR-0454525.
Any opinions, findings and conclusions or recomendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).