HR: 16:15h
AN: V24A-02 INVITED     [Abstracts]
TI: Volcanic Hazard Evaluated Through Monitoring with Thermal Cameras
AU: * Calvari, S
EM: calvari@ct.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia, Piazza Roma 2, Catania, 95123 Italy
AB: Thermal imaging has been introduced in volcanology to analyse a number of different processes, and has been extensively used at INGV-CT since 2001 for monitoring the eruptive activity of Etna, Stromboli and recently also of Vulcano. Thermal mapping allows us to detect magma movements within the summit conduits of volcanoes, and to reveal volcanic activity within the craters even through the thick curtain of gases generally released by Mt. Etna and Stromboli. Thermal mapping is essential during effusive eruptions, because it allows us to distinguish between lava flows of different age, with differences of just one or few days (Andronico et al., 2005). Thermal mapping is essential in revealing the paths of concealed lava tubes (Burton et al., 2005), thus improving hazard evaluation related to lava flow emplacement. Thermal imaging has also been applied to reveal failure planes and instability on the flanks of active cinder cones (Calvari and Pinkerton, 2004). Excellent results have been obtained at INGV-CT in terms of volcanic prediction during the eruptions of Mt Etna and Stromboli, both occurred in 2002-2003. On Etna, thermal images recorded monthly from helicopter on the summit of the volcano revealed the opening of fissure systems several months before the 2002 flank eruption. After the onset of this eruption, daily thermal mapping from helicopter allowed us to monitor a complex lava flow field spreading within a forest, below a thick plume of ash. Fixed thermal cameras deployed near the summit of Etna allowed us to recognize the emission of ash plumes from the summit craters, to identify the crater responsible of such an emission, and to evaluate the area involved by possible fallout. At Stromboli, helicopter-borne thermal surveys allowed us to recognise the opening of fractures along the Sciara del Fuoco, one hour before the large failure that caused destruction on the island on December 2002 (Calvari et al., 2005a). In addition, we were able to follow the exceptional explosive event of the 5th April 2003 at Stromboli from a helicopter with a thermal camera recording images immediately before, during and after the paroxysmal explosion (Calvari et al., 2005b). Harris et al. (2005) applied to thermal images detected during daily surveys a system to calculate instantaneous effusion rate from helicopter-borne thermal images, and this in turn can be used to estimate the maximum extension that a lava flow can attain. We believe that a more extended use of thermal cameras in volcano monitoring, both on the ground and from fixed positions, will significantly improve our understanding of volcanic phenomena and hazard during volcanic crises. Andronico D et al. (2005) - Bulletin of Volcanology, doi:10.1007/s00445-004-0372-8, 67, 314-330. Burton M et al. (2005) - Geophysical Research Letters, vol. 32, L09303, doi:10.1029/2005GL022527. Calvari S & Pinkerton H (2004) - Journal of Volcanology and Geothermal Research, doi:10.1016/S0377-0273(03)00347-0, 132, 225-239. Calvari S et al (2005b) - Journal of Volcanology and Geothermal Research, in print. Calvari S et al. (2005a) - Journal of Geophysical Research, vol 110, B02201, doi:10.1029/2004JB003129. Harris A et al. (2005) - Bulletin of Volcanology, doi:10.1007/s00445-005-0425-7.
DE: 8414 Eruption mechanisms and flow emplacement
DE: 8419 Volcano monitoring (7280)
DE: 8425 Effusive volcanism
DE: 8428 Explosive volcanism
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005