In-Situ Radon Volatilization in an Undrained Fractured Aquifer

Abstract

In-situ radon volatilization offers a practical mechanism for a premonitory decrease in groundwater radon. Our study on large earthquakes in Taiwan from 2003 to 2018 deciphers the mechanism of radon volatilization responsible for the recurrent radon anomalies precursory to large earthquakes, which enables an important application of the mechanism to site a well in suitable geological conditions for a premonitory decrease in groundwater radon. A small low-porosity fractured aquifer in undrained conditions near an active fault is a suitable geological site to detect precursory declines in groundwater radon prior to local large earthquakes. A suitable geological site cited here is Taiwan’s Paihe limestone spring.