Relationships Between Radon Anomalies and Seismic Activities In Tuzla Fault Zone In Western Turkey

Abstract

Seismic activities around the world requires one to investigate and develop new methods for the prediction of earthquakes. The seismic studies provide evidence which indicate that significant variations of radon concentration may occur in association with major geophysical events. In these studies, some predictions have been done using many methods and techniques. One of these methods is to observe variations of radon gas concentration in soil and groundwaters. The Aegean region has allway suffers from several tectonic activities. Izmir and its surrounding located in this region have been frequently effected by earthquakes through historical and antique periods. In this study, possible relationships has been investigated between seismic data and the radiation of radon concentration as a precursor for earthquakes in Doganbey fault zone that has high risk level for Izmir. In this fault zone, radon concentrations in waters and soils have been measured using collector method and nuclear track detectors, respectively. Data given by Bogazici University Kandilli Observatory and Earthquake research Institute was considered in order to correlate with experimental results. The annual radon concentrations measured using collector method in four stations of thermal waters during one year varied from 0.28 Bq L -1 to 11.01 Bq L -1 . The radon concentrations found using nuclear track detectors (LR115) in soils of thermal water fields varied from 50 track cm -2 week -1 to 750 track cm -2 week -1 . Comparing the radon data obtained using both methods with earthquake magnitudes, it could be said that there is a positive correlation between radon emanation rate and seismic activities in the area under investigation.