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University of Wisconsin (USA)
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- PublicationRestrictedNew insights on 3D crustal structure in Southeastern Sicily (Italy) and tectonic implications from an adaptive mesh seismic tomography(2007)
; ; ; ; ; ;Scarfì, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Giampiccolo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Musumeci, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Patanè, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Zhang, H.; University of Wisconsin (USA); ; ; ; The adaptive mesh double-difference tomography algorithm (tomoADD) was applied to absolute and differential P, S and S–P data to determine three dimensional VP, VS and VP/VS variations and event locations in southeastern Sicily (Italy). The obtained velocity images highlight vertical and lateral heterogeneities that can be associated with different geological units and main tectonic features. In particular, the sharp velocity contrasts are consistent with previously recognized active faults, allowing us to better determine their shapes and geometries at depth. Moreover, a striking correspondence between areas ruptured by earthquakes and velocity anomalies is observed. In fact, seismicity is mostly confined in the high velocity volumes and/or along the high–low velocity boundaries at mid-crustal depths, whereas it tends to avoid regions with lower than average VP and VS values and higher VP/VS ratios.325 40 - PublicationOpen AccessTomographic images of a low velocity Vp and Vs volume beneath Stromboli Volcano, Italy(2008-08-18)
; ; ; ; ; ; ; ;Barberi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Cocina, O.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Scarfì, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Castellano, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Chiarabba, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Patanè, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Zhang, H.; University of Wisconsin-Madison, Department of Geology and Geophysics; ; ; ; ; ; The present study is mainly focused to determine the hypocentral locations and the velocity structure between the northeastern Sicily and southern Calabria, including the Aeolian Archipelago with particular regard to Stromboli volcano. The main goals are: i) to explore the differences between relative and absolute earthquake locations, ii) to identify spatial clusters in the seismicity, in order to investigate on the most active seismogenic zones and structures and iii) to recognize the presence of low velocity regions beneath the Aeolian Archipelago related to the presence of partial melting. We applied the TomoDD algorithm which use both absolute and differential arrival times to simultaneously determine event locations and Vp and Vp/Vs velocity models. 1,304 well located events have been considered during the 1994-2006 period. This code was applied to the catalog phase data, combining 11,261 P-wave and 5,751 S-wave arrival time differences. On the basis of the distribution of the events, a denser grid with respect to previous studies was used. This allowed a higher resolution of the velocity model and to find a better correspondence with the most active seismogenic zones and structures. Moreover, being the velocity structure of Stromboli poorly defined, a particular attention was devoted to this area. Tomographic images beneath this volcano revealed the presence of a low Vp and Vs (average values around 5.4 and 3.1 Km/s, respectively) elongated volume in the crust, suggesting the existence of partial melting. This volume extending until 17 km of depth, overlies a high Vp and Vs (values greater than 7.5 and 4.5 km /s, respectively) region that can be related to the Moho.137 81