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  • 1
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    New insights on volcanic and tectonic structures of the southern Tyrrhenian (Italy) from marine and land seismic data (2013)
    American Geophysical Union
    Details
    Publication Date: 2017-04-04
    Description: We present results from the first crustal seismic tomography for the southern Tyrrhenian area, which includes ocean bottom seismometer (OBS) data and a bathymetry correction. This area comprises Mt. Etna, the Aeolian Islands, and many volcanic seamounts, including the Marsili Seamount. The seismicity distribution in the area depends on the complex interaction between tectonics and volcanism. The 3-D velocity model presented in this study is obtained by the inversion of P wave arrival times from crustal earthquakes. We integrate travel time data recorded by an OBS network (Tyrrhenian Deep Sea Experiment), the SN-1 seafloor observatory, and the land network. Our model shows a high correlation between the P wave anomaly distribution and seismic and volcanic structures. Two main low-velocity anomalies underlie the central Aeolian Islands and Mt. Etna. The two volumes, which are related to the well-known active volcanism, are separated and located at different depths. This finding, in agreement with structural, petrography, and GPS data from literature, confirms the independence of the two systems. The strongest negative anomaly is found below Mt. Etna at the base of the crust, and we associate it with the deep feeding system of the volcano. We infer that most of the seismicity is generated in brittle rock volumes that are affected by the action of hot fluids under high pressure due to the active volcanism in the area. Lateral changes of velocity are related to a transition from the western to the central Aeolian Islands and to the passage from continental crust to the Tyrrhenian oceanic uppermost mantle.
    Description: Published
    Description: 3703–3719
    Description: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Description: 3.3. Geodinamica e struttura dell'interno della Terra
    Description: JCR Journal
    Description: open
    Keywords: ocean bottom seismometers ; southern Tyrrhenian Sea ; seismic tomography ; Aeolian Islands ; Etna ; oceanic continental crust ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring ; 04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy ; 04. Solid Earth::04.07. Tectonophysics::04.07.04. Plate boundaries, motion, and tectonics ; 04. Solid Earth::04.07. Tectonophysics::04.07.06. Subduction related processes ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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    PAPER (OA)
  • 2
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    On the seismicity recorded in the geothermal area of Mt. Amiata. (Oral Presentation - ESC2016-461) (2016)
    Details
    Publication Date: 2017-04-04
    Description: Mt. Amiata in Tuscany (Italy) is an extinct volcano whose last eruptive activity was dated about 200 ky ago. Being still characterized by a high geothermal gradient the area lends itself for geothermal exploitation. Beneath the Tuscan Geothermal Areas seismicity is exclusively observed in the upper crust and is confined in depth by the so called K-horizon (400°C isotherme). The structure above contains permeable layers of highly fractured, volcanic rocks saturated with hot water and steam. Geothermal exploitation from these layers started in the 1960’s. Shallow earthquakes have occurred close to the geothermal wells, and the question is raised whether these event are of natural origin or related to the exploitation of heat. To monitor the seismic activity inside the geothermal field, an 8 station seismic network and a 7 element small aperture seismic array were installed in 2015 in the vicinity of the geothermal power plants during a joint field experiment by the Istituto Nazionale di Geofisica e Vulcanologia, the University of Potsdam and the GFZ-German Research Center of Geoscience. Already during the first 24 hours of seismic recording the array and the neighboring network stations recorded a M0.5 seismic event in the vicinity of the geothermal field of Bagnore. Since then micro-earthquake activity was recorded regularly. One of the main challenges of the seismic array/network installation, deployed in direct proximity to the geothermal energy production, is to identify seismic events caused by human operations. As hypocenters are located close to the geothermal power plants, at a similar depth as the production level, it is very difficult - if not impossible - to discriminate between natural earthquakes and anthropogenic events. The main goal of the seismic array/network deployed in the framework of our project is to shed some additional light on this question. The monitoring capabilities of the recording system permit a lowering of the detection threshold for local seismic events, performing high-resolution hypocentral determination, especially in the vicinity of the industrial operations, and calculating focal mechanisms. Array techniques and relative location methods will be used for a precise hypocentral determination. Polarization and spectral analysis, will be applied to discriminate seismic recordings from Mt. Amiata that sometimes resemble rather volcano-seismic waveforms with long-period characteristics, than typical tectonic events.
    Description: European Seismological Commission
    Description: Unpublished
    Description: Trieste, Italy
    Description: 6T. Sismicità indotta e caratterizzazione sismica dei sistemi naturali
    Description: open
    Keywords: Monitoring ; Seismic array ; 04. Solid Earth::04.03. Geodesy::04.03.06. Measurements and monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Oral presentation
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  • 3
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    TOMO-ETNA experiment at Etna volcano: Activities on land (2017)
    Details
    Publication Date: 2022-04-29
    Description: In the present paper we describe the on-land field operations integrated in the TOMO-ETNA experiment carried out in June-November 2014 at Mt. Etna volcano and surrounding areas. This terrestrial campaign consists in the deployment of 90 short-period portable three-component seismic stations, 17 broadband seismometers and the coordination with 133 permanent seismic station belonging to Italy’s Istituto Nazionale di Geofisica e Vulcanologia (INGV). This temporary seismic network recorded active and passive seismic sources. Active seismic sources were generated by an array of air-guns mounted in the Spanish oceanographic vessel “Sarmiento de Gamboa” with a power capacity of up to 5200 cubic inches. In total more than 26,000 shots were fired and more than 450 local and regional earthquakes were recorded. We describe the whole technical procedure followed to guarantee the success of this complex seismic experiment. We started with the description of the location of the potential safety places to deploy the portable network and the products derived from this search (a large document including full characterization of the sites, owners and indication of how to arrive to them). A full technical description of the seismometers and seismic sources is presented. We show how the portable seismic network was deployed, maintained and recovered in different stages. The large international collaboration of this experiment is reflected in the participation of more than 75 researchers, technicians and students from different institutions and countries in the on-land activities. The main objectives of the experiment were achieved with great success.
    Description: Published
    Description: S0427
    Description: 2SR. VULCANI - Servizi e ricerca per la Società
    Description: JCR Journal
    Description: open
    Keywords: Active and passive seismic experiment ; Seismic tomography ; Etna volcano ; Oceanographic vessels ; 04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation Availability
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    PAPER (OA)
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