Preprints
https://doi.org/10.5194/hess-2018-360
https://doi.org/10.5194/hess-2018-360
07 Aug 2018
 | 07 Aug 2018
Status: this discussion paper is a preprint. It has been under review for the journal Hydrology and Earth System Sciences (HESS). The manuscript was not accepted for further review after discussion.

Hydrogeological responses to the 2016 Gyeongju earthquakes, Korea

Jaeyeon Kim, Jungjin Lee, Marco Petitta, Heejung Kim, Dugin Kaown, In-Woo Park, Sanghoon Lee, and Kang-Kun Lee

Abstract. The September 12, 2016 Gyeongju earthquakes (M5.1 and M5.8) had significant effects on groundwater systems along the Yangsan Fault System composed of NNE-trending, right-lateral strike-slip faults in Korea. Hydrological changes induced by the earthquakes are important because no surface ruptures have been reported and few earthquakes usually occur in Korea. The main objective of this research was to propose a conceptual model interpreting the possible mechanisms of groundwater response to the earthquakes based on anomalous hydrogeochemical data including isotope (radon, strontium) concentrations with bedrock characteristics. To analyze the hydraulic changes resulting from the earthquakes, annual monitoring data of groundwater level, temperature, and electrical conductivity and collected data of hydrochemical parameters, radon-222, and strontium isotopes were collected during January 2017. Groundwater level anomalies could be attributed to the movement of the epicentral strike-slip fault. Radon concentration data showed the potential of groundwater mixing processes. Strontium anomalies could be related to the lithology and stratigraphy of the bedrock, reflecting the effect of water–rock interaction. Using a Self-Organizing Map (SOM) statistical analysis, associations of hydro-geochemical characteristics among groundwater wells were interpreted. By combining the grouped results of the SOM with lithostratigraphic unit data, 21 groundwater wells were classified into four groups, each corresponding to different hydrogeological behaviors. A new comprehensive conceptual model was developed to explain possible mechanisms for the hydrological and geochemical responses in each group, which have been respectively identified as water–rock interaction, mixing of shallow and deep aquifers via sea water intrusion, bedrock fracture opening related to strike-slip fault movement, and no response.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Jaeyeon Kim, Jungjin Lee, Marco Petitta, Heejung Kim, Dugin Kaown, In-Woo Park, Sanghoon Lee, and Kang-Kun Lee
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Jaeyeon Kim, Jungjin Lee, Marco Petitta, Heejung Kim, Dugin Kaown, In-Woo Park, Sanghoon Lee, and Kang-Kun Lee
Jaeyeon Kim, Jungjin Lee, Marco Petitta, Heejung Kim, Dugin Kaown, In-Woo Park, Sanghoon Lee, and Kang-Kun Lee

Viewed

Total article views: 2,200 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
1,686 455 59 2,200 65 68
  • HTML: 1,686
  • PDF: 455
  • XML: 59
  • Total: 2,200
  • BibTeX: 65
  • EndNote: 68
Views and downloads (calculated since 07 Aug 2018)
Cumulative views and downloads (calculated since 07 Aug 2018)

Viewed (geographical distribution)

Total article views: 1,950 (including HTML, PDF, and XML) Thereof 1,933 with geography defined and 17 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Latest update: 12 Jun 2024
Download
Short summary
This study analyzed groundwater responses to the earthquake in Korea strongest ever since the instrumental observation begun in 1978. Through a statistical similarity analysis, groundwater chemical and physical responses of observation wells were grouped into 4 patterns. The difference between patterns were explained by appropriate mechanisms. The results indicated a possibility that subsurface conditions related with the earthquake can be characterized by groundwater observations.