Thermal Weakening Friction During Seismic Slip: Experiments and Models With Heat Sources and Sinks

Experiments that systematically explore rock friction under crustal earthquake conditions reveal faults undergo abrupt dynamic weakening. Processes related to heating and weakening of fault surfaces have been invoked explain pronounced velocity Both contact asperity temperature Ta background T the slip zone evolve significantly during high-velocity due heat sources (frictional work), sinks (e.g., latent decomposition processes), diffusion. Using carefully calibrated High-Velocity Rotary Friction experiments, we test compatibility thermal models: (1) a model based only on in an extremely simplified, Arrhenius-like dependence; (2) flash which accounts for evolution both V T; (3) same but including balance; (4) dependence diffusivity capacity. All models reflect experimental results unrealistically low temperatures reproduces restrengthening phase by modifying parameters each condition. The presence dissipative stage affects reflects friction, allowing better joint fit initial final strength recovery across range experiments. Temperature is altered (4). However, similar can be obtained adjusting energy sinks. To compute this type problem, compare efficiency three different numerical approximations (finite difference, wavenumber summation, discrete integral).