Hydrogeochemical characteristics and genesis of Hongshuilantang Hot Spring and its water temperature anomalies during the Rushan earthquake swarm in Eastern China

Water temperatures of hot springs close to tectonic fault zones often show some variations before earthquakes, and analyses earthquake precursors in have significant referential meaning for monitoring forecasting. This study measured the concentration major ions water from Hongshuilantang Hot Spring 2017 2020. The ion composition was classified by hydrochemistry into HCO 3 ·SO 4 -Na chemical type. hydrogen oxygen isotopes were located near global meteoric line (GMWL), indicating that recharge source spring water. ?D ?18O values not plotted on Glogal Meteroric Line there deviations, which suggested underwent water–rock interactions. Deep circulation played an important role during evolution process thermal temperature showed a decreasing trend October 2013 June 2015 Rushan swarm eastern China. Because occurrence swarm, we inferred regional stress this area began be released, allowing continuous rebalancing. Free surface appeared aquifers, seepage low-temperature underground upper aquifer led drop spring. epicenter Muping–Jimo seismological zone, with same seismotectonic system genesis relationships.