title: Spatial distribution of soil radon as a tool to recognize active faulting on an active volcano: the example of Mt. Etna (Italy).
abstract: This study concerns measurements of radon and thoron emissions from soil carried out in 2004 on the eastern flank of Mt. Etna, in a zone characterized by the presence of numerous seismogenic and aseismic faults. The statistical treatment of the geochemical data allowed recognizing anomaly thresholds for both parameters and producing distribution maps that highlighted a significant spatial correlation between soil gas anomalies and tectonic lineaments. The seismic activity occurring in and around the study area during 2004 was analyzed, producing maps of hypocentral depth and released seismic energy. Both radon and thoron anomalies were located in areas affected by relatively deep (5-10 km depth) seismic activity, while less evident correlation was found between soil gas anomalies and the released seismic energy. This study confirms that mapping the distribution of radon and thoron in soil gas can reveal hidden faults buried by recent soil cover or faults that are not clearly visible at the surface. The correlation between soil gas data and earthquakes depth and intensity can give some hints on the source of gas and/or on fault dynamics.
authors.affiliation: Istituto Nazionale di Geofisica e Vulcanologia, Piazza Roma, 2 - 95123 Catania, Italy. marco.neri@ct.ingv.it
authors.forename: Marco
authors.initials: M
authors.lastname: Neri
authors.forename: Salvatore
authors.initials: S
authors.lastname: Giammanco
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Ferrera
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Patanè
authors.forename: Vittorio
authors.initials: V
authors.lastname: Zanon
mesh_terms: D007558:Italy; D011834:Radiation Monitoring; D011886:Radon / Q000032:analysis*; D017687:Radon Daughters / Q000032:analysis; D012987:Soil / Q000737:chemistry*; D012990:Soil Pollutants, Radioactive / Q000032:analysis* / Q000737:chemistry; D018707:Volcanic Eruptions
chemical_list: D017687:Radon Daughters; D012987:Soil; D012990:Soil Pollutants, Radioactive; D011886:Radon