Insights on radon survey at the Stromboli volcano

Abstract

We present an overview of the radon surveys at Stromboli island starting from the 2002, with the aim to better understand the relation between in-soil radon degassing and change in volcanic activity. Radon measurements were performed by means of different, passive, methodologies. By using a radon network of 21 sampling sites, placed in the NE sector of the island, we effected periodic surveys by means of two manually techniques. Track-etch detectors and EPERM electrets allowed us to construct a continuous time-series of radon measurements during the period 2002–2007 and to recognize the short-time variations. Radon activity shows, by means of EPERM® electrets, a wide range of values, from 0.3 to 50 kBq/m3. These data confirm the role of the local effects on the in-soil radon emissions and show that the structural alignments represent a preferential pathways for the radon migration from soil to air. Prom the 2007 we developed two real-time multiparametric, fully automated stations where the measurements of radon activity, acquired every 15 minutes, are correlated with the soil temperature and atmospheric pressure data. The first results show the important role of the atmospheric factors (e.g. soil temperature) in the acquired radon measurements.