Viscoelastic Coulomb stress from historical earthquakes on the 2022 Luding MS6.8 earthquake and its static stress triggering on neighboring faults

We investigated the influence of historical earthquakes on the 2022 Luding M S 6.8 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 because of several historical earthquakes. Specifically, the 1923 Renda M S 7.3 earthquake, the 1933 Diexi M S 7.5 earthquake, the 1973 Luhuo M S 7.3 earthquake, the 2008 Kangding M S 5.1 earthquake, the 2008 Wenchuan M S 8.0 earthquake, the 2014 Kangding M S 6.3 earthquake, and the 2014 Kangding M S 5.8 earthquake advanced the occurrence of the event by 117.61, 26.67, 84.51, 0.27, 0.91, 7.64, and 3.17 years, respectively. Conversely, the 1936 Mabian earthquake swarm, the 1948 Litang M S 7.3 earthquake, the 1955 Kangding M S 7.5 earthquake, and the 2013 Lushan M S 7.0 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 computed the coseismic Coulomb stress changes in neighboring faults. Our results reveal increased Coulomb stress on 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.