3.3. Sensitivity of Stress
We varied only one model parameter to investigate the sensitivity of
stress results for each case, such that all other parameters remained
constant based on the above model setting for the following calculation.
The parameters that were varied include the 1920 Mw 8.5 Haiyuan (No. 10)
and 1927 Mw 8.3 Gulang (No. 11) earthquakes source parameters, the
strike, dip, and rake angles of the Tianzhu Seismic Gap, frictional
coefficient μ’, and the viscosities of the middle and lower crusts. By
considering the uncertainty from all the cases by model
parameterization, including the 1920 Haiyuan and 1927 Gulang earthquakes
source parameters and the receiver fault parameters, we found that the
ΔCFS before 2022 ranged from -27.49 kPa to -1.07 kPa at the 2022 Menyuan
earthquake hypocenter. The minimum ΔCFS decrease after 2022 ranged from
-430.84 kPa to -342.14 kPa and from -184.29 kPa to -18.14 kPa in the
eastern LLLF and western JQFH, respectively. The maximum ΔCFS increase
after 2022 ranged from 229.90 kPa to 562.58 kPa, from 10.66 kPa to
655.50 kPa, from 419.86 kPa to 3359.4 kPa, and from 516.55 kPa to 1755
kPa in the western LLLF (between the 2016 Mw 5.9 [No. 9] and 2022 Mw
6.6 [No.12] Menyuan earthquakes), eastern JQHF, MMSF, and LHSF,
respectively (Text S4 in Supporting Information).