Numerical investigation of heating effect on the earthquake faulting based on the Chester-Higgs model

Rate- and state-dependent friction （RSF） law is an empirical law derived from labo-ratory experiments related to rock friction. RSF law has been used to quantitatively describe complex fault friction processes. Currently, it has emerged as the theoretical basis for the study of seismogenesis and earthquake faulting. With a combination of the Chester-Higgs friction model and the McKenzie-Brune frictional heat generation model, in this study we have investi-gated the effect of frictional heating process on the fault temporal evolution based on a spring-slider-fault system subjected to a rate- and state-dependent friction law. The system equations are solved efficiently by Dormand-Prince method with adaptive steps. The results show that, compared with the case in which the temperature effect is neglected （unheated fault）, the rise of temperature caused by frictional heating can lead to a slight time advance of fault instability, accompanied by abrupt decreases of the friction coefficient and state variable, respectively. In the case when the temperature effect is taken into consideration （heated fault）, the slip and stress drop on the fault are slightly smaller than that on the unheated fault, while the slip rate becomes larger. In addition, the effective normal stress and critical slip distance can also affect the fault temporal evolution. The greater the effective normal stress on the heated fault is, the earlier the fault instability occurs, accompanied with higher temperature rising. The larger the critical slip distance of the heated fault is, the later the fault instability occurs with a significant temperature increase. However, when the critical slip distance is larger than 5 cm, the peak temperatures are almost the same when the fault is unstable.