HR: 0800h
AN: V31A-0601    [Abstracts]
TI: Advancement on Thermal Imaging in Volcanic Areas: Results From a Cross-Calibration Experiment in a Fumarolic Field, Vulcano (Italy)
AU: * Lodato, L
EM: lodato@ct.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Catania, Piazza Roma 2, Catania, 95123 Italy
AU: Dehn, J
EM: jdehn@gi.alaska.edu
AF: Alaska Volcano Observatory, Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska, Fairbanks, AK 99775-7320 United States
AU: Harris, A J
EM: harris@higp.hawaii.edu
AF: HIGP/SOEST, University of Hawai'i, 1680 E-W Rd., Honolulu, Hawaii, HI 96826 United States
AU: Spampinato, L
EM: spampinato-l@ct.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Catania, Piazza Roma 2, Catania, 95123 Italy
AB: Thermal imaging has recently been introduced in volcanology to analyse a range of different volcanic processes. Thermal mapping is essential during effusive eruptions, since it distinguishes lava flows of different age and the paths of concealed lava tubes, thus improving hazard evaluation. Recently, thermal imaging has also been applied to reveal failure planes and slope instability on the flanks of active volcanoes. On Etna, monthly-recorded thermal images on the summit area revealed the opening of fissure systems several months before the eruption onset. After the onset of the flank eruption, daily thermal mapping allowed us to monitor a complex lava flow field spreading within a forest, below a dense ash-laden plume. At Stromboli, helicopter-borne thermal surveys allowed recognising the opening of fractures along the Sciara del Fuoco depression, which led to the formation of a major failure on 30 December 2002, followed by a tsunami event. This was the first time that a volcanic flank collapse had been monitored with a thermal camera. Since 2002, we have carried out helicopter-borne thermal surveys of the Vulcano Fossa and recently, starting from February 2005, we have also recorded thermal images on the ground from different fixed positions to map the fumarole field, using a FLIR 695 thermal camera and a calibrated camera. In July 2005, this methodology was further developed using five FLIR thermal cameras located at different distances from the fumarole field, a Flyspec and two thermocouples. The focus of this experimental test was to evaluate how the maximum fumarole temperatures vary, according to several parameters: distance, relative humidity, atmospheric temperature, surface emissivity, background mixing, aerosol concentrations in the air between the object and the camera, reflection of solar radiation and presence of different gas species, mostly SO2. The determination of these parameters is necessary to perform an internal calibration of the thermal camera in order to correct digital data and obtain a rigorous determination of temperatures of specific targets. Moreover, during the July 2005 survey, we also tested an A 40 thermal camera to be installed in a fixed position to collect thermal images of the fumarole field in real-time. Once collected, data will be transferred to the operation centre and elaborated by a software able to automatically extract the maximum temperatures from the dataset. Results obtained during the recent eruptions of both Stromboli and Etna volcanoes revealed the great potentiality of thermal imaging on tracking different volcanic phenomena and helping in forecast volcanic events. Our future efforts are thus devoted to the development of continuous monitoring and real time acquisition of thermal images in both open vent volcanoes and fumarolic fields.
DE: 8411 Thermodynamics (0766, 1011, 3611)
DE: 8414 Eruption mechanisms and flow emplacement
DE: 8419 Volcano monitoring (7280)
DE: 8485 Remote sensing of volcanoes
DE: 8494 Instruments and techniques
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005