Groundwater oxygen anomaly related to the 2016 Kumamoto earthquake in Southwest Japan

• SANO Yuji

  Atmosphere and Ocean Research Institute, The University of Tokyo Institute of Surface-Earth System Science, Tianjin University

• ONDA Satoki

  Atmosphere and Ocean Research Institute, The University of Tokyo

• KAGOSHIMA Takanori

  Atmosphere and Ocean Research Institute, The University of Tokyo

• MIYAJIMA Toshihiro

  Atmosphere and Ocean Research Institute, The University of Tokyo

• TAKAHATA Naoto

  Atmosphere and Ocean Research Institute, The University of Tokyo

• SHIBATA Tomo

  Institute for Geothermal Sciences, Kyoto University

• NAKAGAWA Chika

  Department of Earth and Environmental Sciences, Kumamoto University

• ONOUE Tetsuji

  Department of Earth and Environmental Sciences, Kumamoto University Department of Earth and Planetary Sciences, Kyushu University

• KIM Nak Kyu

  Unit of Antarctic K-route Expedition, Korea Polar Research Institute

• LEE Hyunwoo

  School of Earth and Environmental Sciences, Seoul National University

• KUSAKABE Minoru

  Department of Environmental Biology and Chemistry, Toyama University

• PINTI Daniele L.

  GEOTOP & Research Center on Earth System Dynamics, Université du Québec à Montréal

Abstract

Here, we report the groundwater oxygen isotope anomalies caused by the 2016 Kumamoto earthquake (M_JMA7.3) that occurred in Southwest Japan on April 16, 2016. One hundred and seventeen groundwater samples were collected from a deep well located 3 km to the southeast of the epicenter in Mifune Town, Kumamoto Prefecture; they were drinking water packed in PET bottles and distributed in the area between April 2015 and March 2018. Further, the oxygen and hydrogen isotopes were evaluated via cavity ring-down spectroscopy without performing any pretreatment. An anomalous increase was observed with respect to the δ¹⁸O value (up to 0.51‰) soon after the earthquake along with a precursory increase of 0.38‰ in January 2016 before the earthquake. During these periods, there was no noticeable change in the hydrogen isotopic ratios. Rapid crustal deformation related to the earthquake may have enhanced the microfracturing of the aquifer rocks and the production of new surfaces, inducing δ¹⁸O enrichment via oxygen isotopic exchange between rock and porewater without changing δ²H.

Journal

• Proceedings of the Japan Academy, Series B

  Proceedings of the Japan Academy, Series B 96 (7), 322-334, 2020-07-31

  The Japan Academy

Keywords

• groundwater
• earthquake precursors
• hydrogen isotopes
• oxygen isotopes
• 2016 Kumamoto earthquake

Details

• CRID: 1390285300182050048
• NII Article ID: 130007887001
• NII Book ID: AA00785485
• DOI: 10.2183/pjab.96.024
• ISSN: 13492896
• ISSN: 03862208
• NDL BIB ID: 030620166
• PubMed: 32788554
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I030620166
• Web Site: https://www.jstage.jst.go.jp/article/pjab/96/7/96_PJA9607B-07/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • PubMed
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed