Citation

Goldsby DL, Tullis TE. Science 2011; 334(6053): 216-218.

Affiliation

Department of Geological Sciences, Brown University, Providence, RI 02912, USA. david_goldsby@brown.edu

Copyright

(Copyright © 2011, American Association for the Advancement of Science)

DOI

10.1126/science.1207902

PMID

21998385

Abstract

The sliding resistance of faults during earthquakes is a critical unknown in earthquake physics. The friction coefficient of rocks at slow slip rates in the laboratory ranges from 0.6 to 0.85, consistent with measurements of high stresses in Earth's crust. Here, we demonstrate that at fast, seismic slip rates, an extraordinary reduction in the friction coefficient of crustal silicate rocks results from intense "flash" heating of microscopic asperity contacts and the resulting degradation of their shear strengths. Values of the friction coefficient due to flash heating could explain the lack of an observed heat flow anomaly along some active faults such as the San Andreas Fault. Nearly pure velocity-weakening friction due to flash heating could explain how earthquake ruptures propagate as self-healing slip pulses.

Language: en