Fig. 1
Tectonic settings of the eastern margin of the Tibet Plateau region. Black star, blue star and yellow stars represent the epicenters of the 2017 Jiuzhaigou earthquake, 2013 Lushan earthquake and historical earthquakes, respectively. The blue circles are the 2017 Jiuzhaigou earthquake 1 day ML > 3 aftershocks, and white circles denote the 2013 Lushan earthquake 1 day ML > 4 aftershocks. The black dash boxes indicate the surface projection of the fault planes used in this study. Focal mechanisms of the 2008 Wenchuan, 2017 Jiuzhaigou and 2013 Lushan earthquakes are also plotted (http://www.globalcmt.org/CMTsearch.html). The inset shows the local tectonic setting. The black lines indicate the major active faults in this region according to Deng et al. (2003a): BY (Beichuan-Yinxiu), DB (Diebu-Bailongjiang), EKL (East Kunlun), HY (Huya), LMS (Longmen Shan), LRB (Longriba), MEK (Maerkang), MJ (Minjiang), MW (Maowen-Wenchuan), PG (Pengxian-Guanxian), PQ (Pingwu-Qingchuan), TZ (Tazang), WLQS (West-Longquanshan) and WX (Wenxian) faults. Location parameters of historical earthquakes are based on the previous studies (Jones et al. 1984; Department of Earthquake Disaster Prevention, China Earthquake Adiministration 1995, 1999; USGS, https://earthquake.usgs.gov/). The thin black lines in the inset map of Fig. 1 are boundaries of first-level blocks in mainland China, and the bold black lines 1 are boundaries of plates