Affiliation:
1. State Key Laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing P.R. China
2. HPT Laboratory Department of Earth Sciences Utrecht University Utrecht The Netherlands
Abstract
AbstractA variety of mechanisms have been proposed to explain how a fault might deform relatively slowly, rather than manifesting as earthquakes. Several rely on the frictional properties of the fault interface. In this study I analyze the slip stability of a fluid‐infiltrated fault in the framework of a microphysically‐based friction model, which has shear zone porosity as its state variable. Linear stability analysis of the model, incorporating the evolution of fluid pressure, gives the critical stiffness () and frequency () as a function of normalized dilatancy () and diffusivity () factors. The theoretical results are similar to those derived from the previous friction laws, except that a positive always exists, even for a highly‐dilatant, impermeable fault where the value is proportional to the diffusivity. This implies that dilatant faults in impermeable media are potentially seismogenic, while the previous models predict negative , implying a stable fault regardless of loading stiffness (k). Adopting a spring‐slider fault analogue, the analytical results are verified numerically under a wide span of spring stiffness, dilatancy, and diffusivity factors. The numerical results further reveal that four different modes of periodic slow slips can emerge in the model, without invoking inertia, which is distinct from previous friction models. Translating into the scenario of an elastically‐deformable medium, the critical wavelength on a dilatant fault can be as long as tens of kilometers. Gaining insights from all these features, I posit that the microphysical model is inherently favorable for generating slow slips.
Funder
National Science Foundation of China
Publisher
American Geophysical Union (AGU)
Subject
Space and Planetary Science,Earth and Planetary Sciences (miscellaneous),Geochemistry and Petrology,Geophysics
Cited by
7 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献