Abstract
Faults can slip seismically or aseismically depending on their hydromechanical properties, which can be measured in the laboratory. Here, we demonstrate that fault slip induced by fluid injection in a natural fault at the decametric scale is quantitatively consistent with fault slip and frictional properties measured in the laboratory. The increase in fluid pressure first induces accelerating aseismic creep and fault opening. As the fluid pressure increases further, friction becomes mainly rate strengthening, favoring aseismic slip. Our study reveals how coupling between fault slip and fluid flow promotes stable fault creep during fluid injection. Seismicity is most probably triggered indirectly by the fluid injection due to loading of nonpressurized fault patches by aseismic creep.
| Original language | English |
|---|---|
| Article number | eaau4065 |
| Journal | Science Advances |
| Volume | 5 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published (in print/issue) - 1 Jan 2019 |
Funding
We thank M. Violay and J. Hazzard for fruitful discussions and P. Segall and one anonymous reviewer for constructive comments. The research presented in this paper is supported by the Agence Nationale de la Recherche (ANR) through the “HYDROSEIS” project under contract no. ANR-13-JS06-0004-01. F.C. was partially supported by the Institut Universitaire de France, and by the French government, through the UCAJEDI Investments in the Future project managed by the ANR with reference no. ANR-15-IDEX-01 at the Université Côte d’Azur. Laboratory experiments have been funded by ERC grant no. 259256 GLASS to C.C. and Marie Sklodowska-Curie grant no. 656676 FEAT to M.M.S.