Questions about examples/2d/subduction step06


I’m currently trying to model spontaneous earthquakes with rate-state friction in subduction zones. I read the section 7.10.9 of the v2.2.1 manual and ran stepo6 successfully. I noticed the reference slip rate used in step06 is 1.0cm/year.
However, in most of the literature I have read on the modeling of spontaneous earthquake in subduction zones, people tend to use 1.0e-6m/s as reference slip rate. Therefore, I tried to change the reference slip rate in step06 to 1.0e-6m/s(Figure 1). And I also changed the state variable to 5.0e+5*s. I didn’t make any other changes, but eventually the non linear solver fails to converge. I wonder what the problem is.


Figure 1

There are a wide range of combinations of reference slip rate, reference friction coefficient, and initial state variable that can produce the same results, provided they yield the same friction and are consistent with the initial conditions. It is important to recognize that the state variable may evolve to a different value depending on your initial conditions, which can lead to different behavior later. You may also need to change your time step when adjust parameters; parameters that lead to more rapid transient behavior will require a smaller time step.