Localization and delocalization of shear in fault gouge from thermal pressurization

Shanna Chu, & Eric M. Dunham

Submitted September 9, 2016, SCEC Contribution #7032, 2016 SCEC Annual Meeting Poster #046 (PDF)

Field observations of extreme shear localization in fault gouge have been attributed to a number of factors, including thermal pressurization. The extent of the localization is affected by various parameters such as diffusion, friction, and gouge width. A model of shear localization due to thermal pressurization developed by Rice et al. (2014) and Platt et al. (2014) imposed a constant slip velocity and solved for the evolution of shear strength. In contrast, we couple the shear zone model to a simple model for elasticity, and solve for the simultaneous evolution of slip velocity and shear strength. This permits examination of not only localization during rapid sliding but also delocalization as the fault decelerates.

We are working on doing complete earthquake cycles in the context of a spring-slider model to examine how shear localizes and delocalizes over the full cycle.

Key Words
thermal pressurization, shear localization, spring-slider model

Citation
Chu, S., & Dunham, E. M. (2016, 09). Localization and delocalization of shear in fault gouge from thermal pressurization. Poster Presentation at 2016 SCEC Annual Meeting.


Related Projects & Working Groups
Fault and Rupture Mechanics (FARM)