Assessment of the Tectonic Effects on Soil Radon Activity Along the Margin of the Arabian Plate Boundary in Northwestern Syria

Abstract

The main purpose of the present study is to assess the role of active tectonics on soil radon emanation level across two tectonically active structures of the Northern Dead Sea Fault (NDSF) northwestern Syria: namely, the Qastoon and the Al-Harif fault segments. Radon measurements were basically directed by the results drawn from earlier archaeoseismic and paleoseismic studies in Al-Harif, besides integrated geophysical and morphotectonic survey at the Qastoon site. A total of 80 soil radon gas measurements were performed at 75 cm sampling depth, using AlphaGUARD PQ 2000Pro radon detector. The background range of normal radon mission from local soil was determined in an area located far from the influence of the tectonic disturbances. The obtained radon data were statistically analyzed and the mean values were standardized in terms of magnitude probability which enhances the comparison process facilitating the separation of normal radon variations from other anomalous or geotectonic related values. The overall results revealed remarkable occurrences of fault-associated radon anomalies with maximum peak values of ~6 to 7 times above the background, trending in accordance with the predicted traces of the fault ruptures at the Qastoon and Al-Harif, respectively.