Project Abstract
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We propose to examine how frictional weakening, shear heating, and the flow of pore fluid and heat together govern the spatial and temporal evolution of fault slip. With past SCEC support we have developed finite difference codes that solve the coupled problem for one dimensional heat and pore-fluid transport normal to the fault, with rate and state friction for a single degree of freedom elastic system. We propose to extend this work to two dimensions (one-dimensional fault) so that rupture nucleation and propagation can be modeled. Segall is supported by a recent NEHRP grant. We seek support for a new Ph.D. student to work on this project during the summer of 2007, and for current Postdoc Takanori Matsuzawa, who will return to ERI (University of Tokyo) in April, to visit Stanford and continue our collaborative research. The proposed research addresses SCEC goals A8-10. Specifically we will test the thermal pressurization mechanism for fault weakening by developing numerical models which can be compared to in situ observations. The numerical methods are sufficiently general that they will allow us to assess the role of material heterogeneity in rupture nucleation and propagation. |
