Vertical depth profiles of absolute (left) and relative (right) shear-wave velocity. Major faults include HYF: Heyuan fault, RZSF: Renzishi fault, DYF: Daping-Yanqian fault, and SCBF: Shijiao-Xingang-Baitian fault. Black dots represent seismic events within 1.5 km of profiles. Red stars mark the locations of earthquakes with magnitude larger than 4.0. The purple arrows indicate possible directions of fluid diffusion. The location of the Xinfengjiang water reservoir (XWR) is represented by the blue quadrilaterals.