title: Time-resolved seismic tomography detects magma intrusions at Mount Etna.
abstract: The continuous volcanic and seismic activity at Mount Etna makes this volcano an important laboratory for seismological and geophysical studies. We used repeated three-dimensional tomography to detect variations in elastic parameters during different volcanic cycles, before and during the October 2002-January 2003 flank eruption. Well-defined anomalous low P- to S-wave velocity ratio volumes were revealed. Absent during the pre-eruptive period, the anomalies trace the intrusion of volatile-rich (>/=4 weight percent) basaltic magma, most of which rose up only a few months before the onset of eruption. The observed time changes of velocity anomalies suggest that four-dimensional tomography provides a basis for more efficient volcano monitoring and short- and midterm eruption forecasting of explosive activity.
authors.affiliation: Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Piazza Roma, 2, 95123, Catania, Italy. patane@ct.ingv.it
authors.forename: D
authors.initials: D
authors.lastname: Patanè
authors.forename: G
authors.initials: G
authors.lastname: Barberi
authors.forename: O
authors.initials: O
authors.lastname: Cocina
authors.forename: P
authors.initials: P
authors.lastname: De Gori
authors.forename: C
authors.initials: C
authors.lastname: Chiarabba