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Free keywords:
radon; soil gas; soil moisture; air pressure; North Anatolian Fault Zone earthquake research;
DDC:
550 - Earth sciences
Abstract:
Abstract: Temporal and spatial variations of radon in soil gas are described in a selected area at the western part of the North Anatolian Fault Zone. This study is carried out in the framework of the German-Turkish Project on Earthquake Prediction Research, aimed at demonstrating the ability for predicting earthquakes. The radon emission in soil gas has been recorded quasi-continuously by plastic nuclear track detectors since 1986/87 at 5 multiparameter observatories along a 60 km segment of the North Anatolian Fault. Furthermore, a radon concentration depth profile is measured continuously by borehole scintillation counters at one station. Annual changes in radon emanation in soil are predominantly caused by changing soil moisture. During summer months it is also affected by air pressure variations. A decreasing pressure in the order of 1 % causes and increase in radon of about 30-50 %. The preliminary results presented in this paper clearly indicate that strong meteorological effects have to be considered when measuring radon in soil gas.
