Abstract:
We investigated the influence of historical earthquakes on the 2022 Luding
MS6.8 earthquake and its subsequent effects. We computed the viscoelastic Coulomb stress changes induced by these historical seismic events using the rupture model of historical earthquakes and the layered Maxwell viscoelastic medium model. Our findings indicate that the Luding earthquake was brought forward approximately 29 years ago because of several historical earthquakes. Specifically, the 1923 Renda
MS7.3 earthquake, the 1933 Diexi
MS7.5 earthquake, the 1973 Luhuo
MS7.3 earthquake, the 2008 Kangding
MS5.1 earthquake, the 2008 Wenchuan
MS8.0 earthquake, the 2014 Kangding
MS6.3 earthquake, and the 2014 Kangding
MS5.8 earthquake resulted in events of 117.61, 26.67, 84.51, 0.27, 0.91, 7.64, and 3.17 years, respectively. Conversely, the 1936 Mabian earthquake swarm, the 1984 Litang
MS7.3 earthquake, the 1955 Kangding
MS7.5 earthquake, and the 2013 Lushan
MS7.0 earthquake delayed its occurrence by 39.89, 22.43, 144.23, and 4.89 years, respectively. Furthermore, by employing the half-space homogeneous elastic model and the rupture characteristics of the Luding earthquake, we compute the coseismic Coulomb stress changes in neighboring faults. Our results reveal increased Coulomb stress in the Xianshuihe fault (excluding its southern segment), the Anninghe fault, the Zemuhe fault, the Daliangshan fault, the southern segment of the Longmenshan fault, the northern segment of the Mabian‒Yanjin fault, and the Xiaojinhe fault. Conversely, we observed stress decreases in the southern segment of the Jinshajiang fault, the central and eastern segments of the Longriba fault, the Mabian-Yanjin fault (excluding its northern segment), and the southern segment of the Xianshuihe fault.