Coseismic slip propagation on the Tohoku plate boundary fault facilitated by slip-dependent weakening during slow fault slip
| Autor: | Kohtaro Ujiie, Matt J. Ikari, Achim J Kopf, Yoshihiro Ito |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
geography
geography.geographical_feature_category 010504 meteorology & atmospheric sciences Subduction Coseismic slip Slip (materials science) Fault (geology) 010502 geochemistry & geophysics 01 natural sciences Foreshock Plate tectonics Geophysics General Earth and Planetary Sciences Episodic tremor and slip Fault slip Geology Seismology 0105 earth and related environmental sciences |
| Zdroj: | Geophysical Research Letters. 44:8749-8756 |
| ISSN: | 0094-8276 |
| Popis: | Slow slip phenomena, including earthquake afterslip and discrete slow slip events (SSE), may have a major effect on megathrust earthquakes in subduction zones, however the nature of this effect is still incompletely understood. Here, we report that in friction experiments using samples from the plate boundary fault zone in the 2011 Tohoku-Oki earthquake, an increase in sliding velocity can induce a change from steady-state frictional strength or slip strengthening friction to slip-weakening frictional behavior. Specifically, significant slip weakening is caused by velocity steps with initial slip rates consistent with afterslip observed after the largest Tohoku earthquake foreshock on March 9th, 2011. This suggests that the foreshock afterslip, which is slightly faster than discrete SSEs, is favorable for fault weakening that may have contributed to the large coseismic slip during the mainshock on the shallow plate boundary fault during the Tohoku-Oki earthquake. |
| Databáze: | OpenAIRE |
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