http://hdl.handle.net/2122/281 Search the Channel search http://www.earth-prints.org/simple-search http://hdl.handle.net/2122/4680 Title: The recent eruptive activity of Mount Etna (Italy) monitored by a network of visible and thermal video cameras <br/> <br/>Authors: Biale, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Mangiagli, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Pecora, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Reitano, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Behncke, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia <br/> <br/>Abstract: The recent eruptive activity of Mount Etna (Italy) monitored by a network of visible and thermal video cameras E. Biale, S. Mangiagli, M. Neri, E. Pecora, D. Reitano and B. Behncke Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, P. Roma, 2 - 95125, Catania Italy (pecora@ct.ingv.it, neri@ct.ingv.it) The recent eruptive activity of Mount Etna in Sicily (Italy) has been well documented by multidisciplinary instrumental observations, and significantly improved the understanding of the eruptive dynamics of this volcano. The monitoring networks are currently developed and managed by the Catania Section of the Istituto Nazionale di Geofisica e Vulcanologia (INGV). Video footage from the network of the monitoring video cameras is analyzed to discriminate between different eruptive typologies and to derive physical and dynamic properties of the eruptions. The cameras are located in four different places around the volcano (Schiena dell’Asino, Milo, Nicolosi and Catania), at respective distances of 5, 11, 15 and 27 km from the summit craters. Four video cameras record in the visible band and one in the Long-wave infrared (LWIR) over 24 hours/day. The images acquired by the Schiena dell’Asino camera are sent to a receiver in Catania, through a 10 GHz microwawe transmitter, whereas the signals from the other cameras are sent to Catania via 2 GHz video transmitters and/or cable. All images are digitized on computer, and archived on video tape and in AVI format with each clip representing 15 minutes compressed using 1 frame per two seconds, which are posted on the intranet server of the institute. A GPS Time-Code ads date and time to each frame before being digitized to 640 x 480 pixels. Meaningful frames are selected for analysis from footage of significant eruptive events, through dedicated software. The cumulative error regarding the measured parameters is estimated at up to 20%. In 2006, a new FLIR Thermavision A40M infrared camera was installed at Nicolosi. The camera detector is a 320 by 240 pixel uncooled microbolometer with a spectral range from 7.5 to 13 micrometer. Vertical and horizontal viewing is 18° and 24 , respectively, with a spatial resolution of 1.3 mrad. Thermal sensitivity is 0.08°C at 30°C. Thermal images are converted on board the camera into a single value for the peak temperature found in a region of interest centred on the active craters. This value is transmitted with a frequency of 1 Hz to the acquisition centre in Nicolosi. If a peak temperature value is less than 2°C than the preceding value then the relative change is added to the cumulative temperature value. Consequently, when the curve is near vertical the images registered by the thermal camera suggest increases in explosive/ effusive activity. On the contrary, if the curve is near horizontal the radiance of the eruptive theatre is constant or in diminution. Thermal images and thermal data are processed by dedicated software developed by LabVIEW 8.0 in detecting ash-rich eruptive columns, explosive and effusive activity. All these data are available at the INGV Control Centre and are used to alert on-duty staff in the early-warning procedures. This network of cameras furnished fundamental data to the Italian Civil Defence during the 2006 eruption, when ash-rich columns several km in height severely threatened the functioning of the nearby International Airport of Catania. http://hdl.handle.net/2122/4652 Title: Thermal Camera Data tool (T.C.D.) per l'analisi dei dati da telecamera termica <br/> <br/>Authors: Russo, G.; Consorzio Cometa; Reitano, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Pecora, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Biale, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia http://hdl.handle.net/2122/4593 Title: Petrology of lavas from the 2004-05 flank eruption of Mt. Etna, Italy: inferences on the dynamics of magma in the shallow plumbing system <br/> <br/>Authors: Corsaro, R. A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Civetta, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Di Renzo, V.; IIstituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Miraglia, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia <br/> <br/>Abstract: Following the 2001 and 2002-03 flank eruptions, activity resumed at Mt. Etna on 7 September 2004 and lasted for about six months. This paper presents new petrographic, major and trace element and Sr-Nd isotope data from sequential samples collected during the entire 2004-05 eruption. The progressive change of lava composition allowed defining three phases that correspond to different processes controlling magma dynamics inside the central volcano conduits. The compositional variability of products erupted up to 24 September is well reproduced by a fractional crystallization model that involves magma already stored at shallow depth since the 2002-03 eruption. The progressive mixing of this magma with a distinct new one rising within the central conduits, is clearly revealed by the composition of the products erupted from 24 September to 15 October. After 15 October, the contribution from the new magma gradually becomes predominant and the efficiency of the mixing process ensures the emission of homogeneous products up to the end of the eruption. Our results give insights into the complex conditions of magma storage and evolution in the shallow plumbing system of Mt. Etna during a flank eruption. Furthermore, they confirm that the 2004-05 activity at Etna was triggered by regional movements of the eastern flank of the volcano. They caused the opening of a complex fracture zone extending ESE which drained a magma stored at shallow depth since the 2002-03 eruption. This process favored the ascent of a different magma in the central conduits, which began to be erupted on 24 September without any significant change in eruptive style, deformation and seismicity till the end of eruption http://hdl.handle.net/2122/4587 Title: Textural and Compositional Characteristics of Lavas Emitted During the December 2002 to July 2003 Stromboli Eruption (Italy): Inferences on Magma Dynamics <br/> <br/>Authors: Landi, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Francalanci, L.; Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Florence, Italy; Corsaro, R. A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Petrone, C. M.; Fornaciai, A.; Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Florence, Italy; Carrol, M. R.; Dipartimento di Scienze della Terra, Università degli Studi di Camerino, Camerino, Italy; Nardini, I.; Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Florence, Italy; Miraglia, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia <br/> <br/>Abstract: Periodic lava sampling was carried out at the active vents during the entire duration of the 28 December 2002 to 22 July 2003 effusive eruption. Major and trace element bulk rock analyses were performed at different laboratories, thereby acquiring four independent sets of analysis. Nd and Sr isotope ratios were obtained on whole rocks and groundmasses, together with micro-Sr isotope analyses on plagioclase and clinopyroxene by microdrilling technique. Crystal size distribution, mineral, and glassy matrix chemistry were analyzed on selected samples. The products show a fairly homogeneous composition, close to that of the crystal-rich scoria that erupted in the previous years. Slight variations of trace elements and isotope ratios between products that erupted before and after the 5 April paroxysm are likely accounted for by limited mixing between the fresh, volatile-rich magma that erupted during the paroxysm and the volatile-poor magma feeding the lava flow. Micro-Sr isotope data show large isotopic disequilibria pointing to the persistence of highly Sr-radiogenic xenocrysts or crystal cores in the shallow magmatic system, probably recycled from the previous activity. Data rule out important changes in the dynamics of the plumbing system shortly before the eruption. A discrete input of deep magma into the lower part of the shallow system some months before the eruption may be at the origin of the increase of the magmatostatic pressure in the conduits, leading to the effusive eruption. An alternative hypothesis considers a nearly steady-state feeding system undergoing gradual, long-term pressure increase in its upper part, eventually leading to periodic lava effusions.