The 2022 Menyuan earthquake occurred in the Qilian-Haiyuan fault system
in northeastern Tibet. To investigate the reason behind this earthquake
and the seismic hazards of the Tianzhu Seismic Gap, we demonstrated the
spatiotemporal stress variation on the fault system before and after
2022 through numerical modelling. We found that the 2022 earthquake was
delayed due to a stress shadow caused by historical earthquakes. This
stress shadow also covers the middle of the Tianzhu Seismic Gap and
prohibits its seismic activities to some extent. Acting as a stress
barrier to prevent the Tianzhu Seismic Gap rupturing in one event, this
stress shadow may decrease the possibility of generating a future
earthquake of magnitude more than Mw7.7 in this gap. The east portion of
the Tianzhu Seismic Gap was stress loaded, indicating its increased
seismic hazards. Attention should be paid to the hazards prevention in
the eastern portion of the gap.