Acoustically induced slip in sheared granular layers: Application to dynamic earthquake triggering: TRIGGERED SLIP IN SHEARED GRANULAR GOUGE
- Swiss Federal Inst. of Technology, Zurich (Switzerland). Dept. of Civil, Environmental and Geomatic Engineering; Swiss Federal Lab. for Materials Science and Technology, Dubendorf (Switzerland)
- Swiss Federal Lab. for Materials Science and Technology, Dubendorf (Switzerland)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Solid Earth Geophysics Group; Univ. of Nevada, Reno, NV (United States). Dept. of Physics
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Solid Earth Geophysics Group
- Pennsylvania State Univ., University Park, PA (United States). Dept. of Geosciences and G3 Centre and Energy Inst.
- Swiss Federal Lab. for Materials Science and Technology, Dubendorf (Switzerland); Swiss Federal Inst. of Technology, Zurich (Switzerland). Chair of Building Physics
A fundamental mystery in earthquake physics is “how can an earthquake be triggered by distant seismic sources?” We use discrete element method simulations of a granular layer, during stick slip, that is subject to transient vibrational excitation to gain further insight into the physics of dynamic earthquake triggering. We also observe delayed triggering of slip in the granular gouge, using Coulomb friction law for grains interaction. We find that at a critical vibrational amplitude (strain) there is an abrupt transition from negligible time-advanced slip (clock advance) to full clock advance; i.e., transient vibration and triggered slip are simultaneous. Moreover, the critical strain is of order 10-6, similar to observations in the laboratory and in Earth. The transition is related to frictional weakening of the granular layer due to a dramatic decrease in coordination number and the weakening of the contact force network. Associated with this frictional weakening is a pronounced decrease in the elastic modulus of the layer. The study has important implications for mechanisms of triggered earthquakes and induced seismic events and points out the underlying processes in response of the fault gouge to dynamic transient stresses.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE; National Science Foundation (NSF)
- Grant/Contract Number:
- AC52-06NA25396
- OSTI ID:
- 1340921
- Report Number(s):
- LA-UR-16-22288
- Journal Information:
- Geophysical Research Letters, Vol. 42, Issue 22; ISSN 0094-8276
- Publisher:
- American Geophysical UnionCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Estimating Fault Friction From Seismic Signals in the Laboratory
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journal | February 2018 |
Viewing Earth’s surface as a soft-matter landscape
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journal | October 2019 |
Analogue earthquakes and seismic cycles: experimental modelling across timescales
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journal | January 2017 |
Analogue earthquakes and seismic cycles: Experimental modelling across timescales
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posted_content | December 2016 |
| Estimating Fault Friction from Seismic Signals in the Laboratory | text | January 2017 |
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