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An anomalous radon decrease in groundwater prior to an M6.0 earthquake: A possible precursor?
Author(s) -
Wakita Hiroshi,
Igarashi George,
Notsu Kenji
Publication year - 1991
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/91gl00824
Subject(s) - artesian aquifer , groundwater , radon , geology , hydrology (agriculture) , aquifer , groundwater flow , environmental science , seismology , geotechnical engineering , physics , quantum mechanics
A. significant decrease in the radon concentration of artesian groundwater was observed at a well‐established observation site in Northeast Japan about two days before an M6.0 earthquake occurred about 200 km from the site. On the basis of a concurrent in situ (−126m) temperature drop of the groundwater, we infer that precursory changes in regional stress were locally amplified near this site and resulted in the temporary mixing of cooler, radon‐poor groundwater into the normal artesian flow.