Illuminating the physics of dynamic friction through laboratory earthquakes on thrust faults
Abstract
Large, destructive earthquakes often propagate along thrust faults including megathrusts. The asymmetric interaction of thrust earthquake ruptures with the free surface leads to sudden variations in fault-normal stress, which affect fault friction. Here, we present full-field experimental measurements of displacements, particle velocities, and stresses that characterize the rupture interaction with the free surface, including the large normal stress reductions. We take advantage of these measurements to investigate the dependence of dynamic friction on transient changes in normal stress, demonstrate that the shear frictional resistance exhibits a significant lag in response to such normal stress variations, and identify a predictive frictional formulation that captures this effect. Properly accounting for this delay is important for simulations of fault slip, ground motion, and associated tsunami excitation.
Additional Information
© 2020 National Academy of Sciences. Published under the PNAS license. Contributed by Ares J. Rosakis, April 15, 2020 (sent for review March 11, 2020; reviewed by Philippe H. Geubelle and Yonggang Huang). PNAS first published August 17, 2020. This study was supported by the NSF (Grant EAR-1651235), the US Geological Survey (USGS) (Grant G20AP00037), Caltech/Mechanical and Civil Engineering Big Idea Fund (2019), Caltech's Division of Geological and Planetary Sciences, and the Southern California Earthquake Center (SCEC) (Contribution 19093). SCEC is funded by NSF Cooperative Agreement EAR-1033462 and USGS Cooperative Agreement G12AC20038. Data Availability: The time series of slip, sliding velocity, and shear and normal stresses near the free surface are available at the Caltech Research Data Repository: https://data.caltech.edu/records/1405. Author contributions: Y.T., V.R., A.J.R., and N.L. designed research; Y.T., V.R., A.J.R., and N.L. performed research; Y.T. analyzed data; and Y.T., V.R., A.J.R., and N.L. wrote the paper. Reviewers: P.H.G., University of Illinois at Urbana–Champaign; and Y.H., Northwestern University. The authors declare no competing interest. This article contains supporting information online at https://www.pnas.org/lookup/suppl/doi:10.1073/pnas.2004590117/-/DCSupplemental.Attached Files
Published - 21095.full.pdf
Supplemental Material - pnas.2004590117.sapp.pdf
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Additional details
- PMCID
- PMC7474586
- Eprint ID
- 104990
- DOI
- 10.1073/pnas.2004590117
- Resolver ID
- CaltechAUTHORS:20200818-083332830
- EAR-1651235
- NSF
- G20AP00037
- USGS
- Caltech Division of Engineering and Applied Science
- Caltech Division of Geological and Planetary Sciences
- Southern California Earthquake Center (SCEC)
- EAR-1033462
- NSF
- G12AC20038
- USGS
- Created
-
2020-08-18Created from EPrint's datestamp field
- Updated
-
2022-11-15Created from EPrint's last_modified field
- Caltech groups
- Center for Geomechanics and Mitigation of Geohazards (GMG), Division of Geological and Planetary Sciences, GALCIT, Seismological Laboratory
- Other Numbering System Name
- Southern California Earthquake Center
- Other Numbering System Identifier
- 19093