title: Soil radon measurements as a potential tracer of tectonic and volcanic activity.
abstract: In Earth Sciences there is a growing interest in studies concerning soil-radon activity, due to its potential as a tracer of numerous natural phenomena. Our work marks an advance in the comprehension of the interplay between tectonic activity, volcanic eruptions and gas release through faults. Soil-radon measurements, acquired on Mt. Etna volcano in 2009-2011, were analyzed. Our radon probe is sensitive to changes in both volcanic and seismic activity. Radon data were reviewed in light of the meteorological parameters. Soil samples were analyzed to characterize their uranium content. All data have been summarized in a physical model which identifies the radon sources, highlights the mechanism of radon transport and envisages how such a mechanism may change as a consequence of seismicity and volcanic events. In the NE of Etna, radon is released mainly from a depth of <1400 m, with an ascent speed of >50 m/day. Three periods of anomalous gas release were found (February 2010, January and February 2011). The trigger of the first anomaly was tectonic, while the second and third had a volcanic origin. These results mark a significant step towards a better understanding of the endogenous mechanisms that cause changes in soil-radon emission at active volcanoes.
authors.affiliation: Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Sezione di Catania, Piazza Roma, 2-95123 Catania, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Neri
authors.affiliation: Dipartimento di Scienze Biologiche, Geologiche e Ambientali - Università di Catania. C.so Italia 57, 95129 Catania, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Ferrera
authors.affiliation: Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Sezione di Catania, Piazza Roma, 2-95123 Catania, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Giammanco
authors.affiliation: Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Sezione di Catania, Piazza Roma, 2-95123 Catania, Italy.
authors.forename: Gilda
authors.initials: G
authors.lastname: Currenti
authors.affiliation: Dipartimento di Scienze Biologiche, Geologiche e Ambientali - Università di Catania. C.so Italia 57, 95129 Catania, Italy.
authors.forename: Rosolino
authors.initials: R
authors.lastname: Cirrincione
authors.affiliation: Dipartimento di Scienze Biologiche, Geologiche e Ambientali - Università di Catania. C.so Italia 57, 95129 Catania, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Patanè
authors.affiliation: Centro de Vulcanologia e Avaliação de Riscos Geológicos, Universidade dos Açores, Ponta Delgada, Portugal.|Institut de Physique du Globe de Paris, 1, rue Jussieu - 75238 Paris cedex 05, France.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Zanon