EFFECT OF FRICTIONAL HEATING ON PRE-SEISMIC SLIDING: A NUMERICAL SIMULATION USING A RATE-, STATE- AND TEMPERATURE-DEPENDENT FRICTION LAW

Abstract

Using a simple spring-block model and a rate- and state-dependent friction law incorporating the effect of temperature variation, I perform a numerical simulation of aseismic sliding prior to unstable (seismic) faulting. I compare the simulation result of pre-seismic sliding in the case where the temperature effect due to frictional heating on frictional strength is taken into consideration (heated fault) with the result in the case where the temperature effect is neglected (unheated fault), assuming model parameters appropriate for the nucleation site of a large interplate earthquake. It is found that an earthquake occurrence time is a little earlier on the heated fault than on the unheated fault. This is because the frictional strength is weakened by temperature rise due to frictional heating during pre-seismic sliding. The amplitude of precursory crustal deformation caused by pre-seismic sliding on the heated fault is estimated to be about 20 per cent smaller than that on the unheated fault.