Study on potential earthquake risk of unbroken active faults in the northern segment of the North-South seismic zone

In the northern segment of the North-South seismic zone there are unbroken active faults, on which no MSge;7.0 earthquakes have occurred for a long time. These faults can be identified by jointly investigating active tectonics and faulting pattern of strong earthquakes in this region. A viscoelastic stress model is used to estimate the potential earthquake risk on these unbroken active faults. This model could aptly describe transient coseismic elastic response and short-term postseismic exponential strain relaxation. Based on the evolution model of Coulomb failure stress, the spatial pattern of seismicity following the Dieterich rate- and state-dependent constitutive law was calculated. The result of earthquake damage probability estimation indicates that the regions having the risk level from high to low are sequentially the Ruoergai-Jiuzhaigou region of east Kunlun fault, middle and southern Liupanshan fault, Tongxin region of middle and southern Xiangshan-Tianjingshan fault, Tianzhu-Dajing region, middle and west segments of western Qinling Mountain fault and east segment of western Qinling Mountain fault.