A study of earthquake recurrence based on a one-body spring-slider model in the presence of thermal-pressurized slip-weakening friction and viscosity

Abstract

Earthquake recurrence is studied from the temporal variation in slip through numerical simulations based on the normalized form of equation of motion of a one-body spring-slider model with thermal-pressurized slip-weakening friction and viscosity. The wear process, whose effect is included in the friction law, is also taken into account in this study. The main parameters are the normalized characteristic displacement, U c , of the friction law and the normalized damping coefficient (to represent viscosity), η. T R , D, and τ D are the recurrence time of events, the final slip of an event, and the duration time of an event, respectively. Simulation results show that T R increases when U c decreases or η increases, D and τ D decrease with increasing η, and τ D increases with U c . The time-and slip-predictable model can describe the temporal variation in cumulative slip. When the wear process is considered, the thickness of slip zone, h, which depends on the cumulated slip, S(t) = D(t), i.e., h(t) = CS(t) (C is a dimensionless increasing rate of h with S), is an important parameter influencing T R and D. U c is a function of h and thus depends on cumulated normalized slip, U , with an increasing rate of C. In the computational time period, the wear process influences the recurrence of events and such an effect increases with C when C > 0.0001. When viscosity is present, the effect due to wear process becomes stronger. Both T R and D decrease when the fault becomes more mature, thus suggesting that it is more difficult to produce large earthquakes along a fault when it becomes more mature. Neither the time-predictable nor the slip-predictable model can describe the temporal variation in cumulative slip of earthquakes under the wear process with large C.

A review on precursors of the 1999 Mw7.6 Chi-Chi, Taiwan, earthquake

“…Numerous factors, including wear process, friction, plasticity, strain rate etc., can influence the pattern of earthquake occurrence. Wear process (Wang 2018b) and time-strengthening static friction (Wang 2020) on a fault are two major factors in influencing the pattern of earthquake recurrence.…”

“…Up to date, this is still a difficult challenge for earthquake scientists, even though there have been some physical models (cf. Wang 2016Wang , 2017Wang , 2018bWang , 2020Wang , 2021 and cited references therein).…”

A review on studies of the 1999 Chi-Chi Earthquake for resolving the debatable problems in earthquake physics

“…The slip duration is almost the rise time at a point on the source area. Wang (2018b) showed that the rise time increases with a decrease in the characteristic slip distance of a frictional law and an increases in either viscosity or inertia of fault-zone materials. The thickness of heated layer can affect the viscous stress.…”

“…For the perfect periodic model, the width, w, of a fault zone must be constant. In fact, numerous factors, including wear process, plasticity, strain rate etc., can change the value of w and thus influence the type of earthquake occurrence (see Wang 2018b). Wang (2018a) studied the effect of wear process in the fault zone on earthquake recurrence.…”

“…Satake (2018) showed irregular recurrent earthquakes in Japan. A detailed descript can be found in Wang (2018b).…”