Real time monitoring of radon as an earthquake precursor in Iceland

We report radon data collected during 1980 from geothermal wells in Iceland. Discrete radon samples are being collected weekly from nine stations in the Southern Iceland Seismic Zone (SISZ) and two stations in the Northern Iceland-Tjornes Fracture Zone (TFZ) to determine the potential for earthquake prediction. We also monitor volume ratio of gas to water, wellhead temperature and chloride content of the water to enable us to constrain the possible mechanism involved in radon anomalies.

We report a possible strain event in April that caused both changes in radon emission and a small earthquake swarm. An eruption at Hekla in August was not preceded by any distinctive radon anomalies. Swarm activity occurring close to Selfoss and Oxnalaekur appeared to be associated with possible low amplitude (