Groundwater helium anomaly reflects strain change during the 2016 Kumamoto earthquake in Southwest Japan.

ABSTRACT: Geochemical monitoring of groundwater and soil gas emission pointed out precursor and/or coseismic anomalies of noble gases associated with earthquakes, but there was lack of plausible physico-chemical basis. A laboratory experiment of rock fracturing and noble gas emission was conducted, but there is no quantitative connection between the laboratory results and observation in field. We report here deep groundwater helium anomalies related to the 2016 Kumamoto earthquake, which is an inland crustal earthquake with a strike-slip fault and a shallow hypocenter (10 km depth) close to highly populated areas in Southwest Japan. The observed helium isotope changes, soon after the earthquake, are quantitatively coupled with volumetric strain changes estimated from a fault model, which can be expl

SUBMITTER: Sano Y 

PROVIDER: S-EPMC5126567 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature