TY - JOUR
T1 - Anomalous change in atmospheric radon concentration sourced from broad crustal deformation
T2 - A case study of the 1995 Kobe earthquake
AU - Yasuoka, Yumi
AU - Kawada, Yusuke
AU - Omori, Yasutaka
AU - Nagahama, Hiroyuki
AU - Ishikawa, Tetsuo
AU - Tokonami, Shinji
AU - Hosoda, Masahiro
AU - Hashimoto, Tetsuo
AU - Shinogi, Masaki
N1 - Funding Information:
We would like to thank Prof. M. Furukawa for the detailed information about measuring the Rn exhalation rate at the main Rokko fault system in Kobe. We are also grateful to Prof. M. Shimo for his valuable discussion throughout our studies. We would like to express thanks to the reviewers for the helpful comments which brought clarity to the revised paper. This study was supported by the Earthquake Research Institute cooperative research program of the University of Tokyo, Japan.
PY - 2012/4
Y1 - 2012/4
N2 - Before the Kobe earthquake, an anomalous increase in atmospheric Rn concentration was observed. By separating the measured concentration of atmospheric Rn into three components according to the distance from the monitoring station, the variation of Rn exhalation rate can be estimated for the respective area using the daily minimum and maximum concentrations. The mean rate of Rn exhalation gradually increased in an area of 20km around the monitoring station, becoming five times higher than normal in the period between October 1994 and the date of the earthquake. This area had a large co-seismic displacement of up to 30cm, which roughly corresponds to the crustal strain of 10 -6-order, and it is considered the main source for the atmospheric Rn prior to the Kobe earthquake. Analyses revealed that the pre-seismic change in the atmospheric Rn concentration exhibited an anomalous pattern which would yield information on the spatial distribution of the mechanical response of the ground.
AB - Before the Kobe earthquake, an anomalous increase in atmospheric Rn concentration was observed. By separating the measured concentration of atmospheric Rn into three components according to the distance from the monitoring station, the variation of Rn exhalation rate can be estimated for the respective area using the daily minimum and maximum concentrations. The mean rate of Rn exhalation gradually increased in an area of 20km around the monitoring station, becoming five times higher than normal in the period between October 1994 and the date of the earthquake. This area had a large co-seismic displacement of up to 30cm, which roughly corresponds to the crustal strain of 10 -6-order, and it is considered the main source for the atmospheric Rn prior to the Kobe earthquake. Analyses revealed that the pre-seismic change in the atmospheric Rn concentration exhibited an anomalous pattern which would yield information on the spatial distribution of the mechanical response of the ground.
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U2 - 10.1016/j.apgeochem.2011.12.018
DO - 10.1016/j.apgeochem.2011.12.018
M3 - Article
AN - SCOPUS:84857801153
VL - 27
SP - 825
EP - 830
JO - Applied Geochemistry
JF - Applied Geochemistry
SN - 0883-2927
IS - 4
ER -