EGU23-4701, updated on 22 Feb 2023
https://doi.org/10.5194/egusphere-egu23-4701
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Evaluating groundwater responses to earthquakes using hydrological and environmental tracer data

Dugin Kaown1, Dong-Chan Koh2, Jaemin Lee2, Jaeyoun Kim1, and Kang-Kun Lee2
Dugin Kaown et al.
  • 1Seoul National University, School of Earth and Environmental Sciences, Seoul, Korea, Republic of
  • 2Korea Institute of Geoscience and Mineral Resources, Daejeon 34132, Republic of Korea

Environmental tracer data were applied to assess chemical signatures of deep fluid in the fault zones in the southeastern part of South Korea. After MW 5.5 Pohang Earthquake in November 2017, hydrogeochemical and environmental tracer data from groundwater samples around epicenter were monitored from 2017 to 2021. Monitoring wells significantly responded to the earthquakes were selected to evaluate temporal variations of environmental tracer data in the groundwater system. The southeastern part of South Korea shows a distinctive NNE-directed geomorphological feature with several strike-slip fault systems and two wells are closely located to this fault. One monitoring station, KW5, is closely located to the Ulsan Fault, which is a reverse. 3He/4He was slightly increased in most of groundwater samples from monitoring wells after MW 5.5 Pohang Earthquake, while 3He/4He decreased in some groundwater samples from wells around reverse fault (Ulsan fault). Especially, 3He/4He in the wells of KW5 station closely located to the Ulsan Fault considerably decreased after the earthquake. However, the concentrations of Na, Ca, SO4 and HCO3 increased around wells in Ulsan Fault after the earthquake. In this study, the response of aquifer system after earthquakes was compared to assess the differences in chemical changes of fluid around strike-slip and reverse faults using hydrogeochemical and environmental tracer data.

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2022R1A5A1085103).

How to cite: Kaown, D., Koh, D.-C., Lee, J., Kim, J., and Lee, K.-K.: Evaluating groundwater responses to earthquakes using hydrological and environmental tracer data, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-4701, https://doi.org/10.5194/egusphere-egu23-4701, 2023.