Environmental monitoring of radon in soil during a very seismically active period occurred in South West Greece.
This paper focuses on the environmental monitoring of radon in soil as a potential trace gas in the search of earthquake precursors. The paper reports the following: (a) Pre-monitoring experiments. (b) Set-up of methods and devices. (c) Active and passive monitoring results concentrating on two extremely-strong radon anomalies (~ 500 kBq m(-3)). (e) Discussion regarding the employed ± 2σ technique for identifying radon disturbances. (f) Application of wavelet-power-spectrum fractal analysis for detecting power-law behaviour. The strong anomalies exhibited anti-persistent power-law-beta-values (b = (1.8 ± 0.2), b = (1.8 ± 0.3)) significantly higher than those of the baseline. Persistent b-values were also detected. The findings comply with a self-organised-critical pre-earthquake state. (h) Discussion on models that interpret the radon anomalies focusing on the recently-proposed asperity-model. (i) Application of a recent technique which showed that the two strong disturbances were proportional to the strain change. It was concluded that the strong radon disturbances may be linked to the strong earthquake of 8/6/2008, M = 6.5, occurred 29 km away from the installed instrumentation.
Department of Physics, Chemistry and Material Science, Technological Educational Institution of Piraeus, Petrou Ralli & Thivon 250, 122 44 Aigaleo, Athens, Greece. dniko@teipir.gr
Dimitrios
D
Nikolopoulos
Ermioni
E
Petraki
Anna
A
Marousaki
Stelios M
SM
Potirakis
Grigorios
G
Koulouras
Constantinos
C
Nomicos
Dionisios
D
Panagiotaras
John
J
Stonham
Anna
A
Louizi
D000396:Air Pollutants, Radioactive / Q000032:analysis*; D055593:Geological Phenomena; D006115:Greece; D011834:Radiation Monitoring; D011886:Radon / Q000032:analysis*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
D000396:Air Pollutants, Radioactive; D012990:Soil Pollutants, Radioactive; D011886:Radon