Chessboard Distribution Caused by Subfaults in Distributed Slip Model

Dear PyLith team,

I used Pylith to simulate a seismic rupture model with over 200 subfaults. and I set each subfault as an independent fault surface in Pylith for the calculations. However, due to the boundaries of the intersecting fault surfaces being forced to 0, the results show a pronounced chessboard-like pattern, especially as the calculations approach the fault surfaces. For the displacement field, the results on the surface are already usable, but for the stress field, the distribution is quite chaotic. I am interested in calculating the changes in δCFS on the fault

What method should I use to calculate the varying slip distribution across the subfaults for the seismic event?

Thank you for your feedback!

PyLith is designed to simulate slip on a fault surface as one continuous field as opposed to using subfaults. In PyLith v3 and later, you can set the basis order to control how slip is discretized over the fault surface. For example, a basis order of 0 gives uniform slip patches over fault cells whereas a basis order of 1 gives piecewise linear slip and a basis order of 2 gives piecewise quadratic variations in slip. If you provide more information about the how you want to use PyLith, then we may be able to provide more specific guidance.

Dear Aagaard,

Thank you for your patient response. Based on your suggestions, I looked into Step 4: Variable Coseismic Slip in the strike2d example. I am now studying and trying to use the method described in the example to address the issue with the subfaults. If I encounter any problems, I will reach out to you again for further guidance.

Thank you very much for your assistance!