Indoor Radon monitoring as a useful predictor of earthquake occurrences in the Balkan region

Abstract

This study deals with continuous radon monitoring conducted to estimate the relationship between indoor radon measurements and potential occurrences of earthquake in the Balkan region. Radon monitoring was performed with the detector Airthings Corentium Home placed in the basement office of faculty building in Kosovska Mitrovica (N 42.897°, E 20.867°) in winter period of the 2020/21 (four months in continuity). According to the European Seismic Hazard Map this region is classified as moderate hazard area. Radon daily variations were noted and analyzed with the earthquakes of magnitude M>2.0 which occurred in forthcoming days in the Balkan region. Anomalous emanation of geo-gases are connected with the ground shaking, and spike-like peaks in radon concentrations could be caused by seismic events in the wider area. In monitoring site it was reflected like a gradual increase in radon concentrations, then a sharp drop (e.g. from 865 Bq/m3 to 73 Bq/m3 within 48 hours). About seven days later an earthquake of magnitude M=2.2 occurred at the distance of 10 km from measuring site, and has been followed with a series of earthquakes in the region. The results seem to indicate that radon is a good indicator of crustal activity and seismic movements.