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Abstract

Induced seismic activity is becoming more and more severe in recent years near the southeast of the Sichuan basin, China, as the rapid development of Shale Gas exploitation around the local area. An MS 5.7 earthquake occurred near Xingwen County on 16 December 2018 within the Sichuan basin which is the largest hydraulic fracturing (HF) earthquake in China to date and caused ground motions intense enough to be felt, triggered landslides, caused ￥50 million in direct economic losses, injuries, and resulted in the first fatalities. Besides, 8 MS≥5.0 earthquakes have occurred Southeast of the Sichuan basin since 2018 supposedly either caused by HF operation or induced by wastewater disposal, where seismic activity has been low historically. The tomoDD double-difference tomography method has been applied to get the high-resolution three-dimensional structures, along with accurate locations of small earthquakes in the study area, taking advantage of 21 mobile stations’ temporary network. Combined with the inverted structure and events’ location data, along with the local geological structural information, we had a better understanding of the seismogenic structures of some moderate to strong earthquakes that occurred in the Sichuan basin. This study can help to establish a suitable regulation controlling system for the safe development of shale gas resources in the Southeast of the Sichuan basin as there is no one yet to date.