3. Stress results
We calculate the combined ΔCFS before and after the 2022 Mw 6.6 Menyuan earthquake, caused by 12 historical earthquakes in and around the Qilian-Haiyuan fault system from 1920 to 2022. The calculated ΔCFS includes contributions from the co-seismic stress changes and postseismic stress relaxation. The viscosities of the middle and lower crusts and the mantle can be found in Table S2 (Supporting Information Text S2), and more details of the visco-elastic model can be found in the Supporting Information.