HR: 0800h
AN: V21A-0387    [Abstracts]
TI: Thermal observations of the degassing of the December 2006 and May 2007 pyroclastic flow deposits at Bezymianny Volcano, Kamchatka
AU: * van Manen, S M
EM: saskia.van-manen@open.ac.uk
AF: Volcano Dynamics Group, Department of Earth Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom
AU: Carter, A J
EM: ajc44@pitt.edu
AF: Department of Geology and Planetary Science, University of Pittsburgh, 200 SRCC Building, 4107 O'Hara Street, Pittsburgh, PA 15260, United States
AB: Bezymianny Volcano (Kamchatka, Russia) has been periodically active since its reawakening in 1956, most recently erupting on December 24, 2006 and May 11, 2007. Currently, one or two eruptive cycles occur each year, consisting of spine emplacement followed by an explosive eruption accompanied by pyroclastic flows, concluding with extrusion of a lava flow. During August 2007, systematic depth profiles of temperatures of the December 2006 and May 2007 pyroclastic flow deposits (PFDs) were obtained in seven satellite-derived target locations using an Omega HH509 thermocouple. In addition, 38 fumarole temperatures were obtained and Forward Looking Infrared Radiometer (FLIR) data were collected throughout the target areas. Degassing of the PFDs was observed through large clusters and linear arrays of fumaroles located in depressions with distinct rocky centres. Hot depressions were also observed without active fumaroles, suggesting that hydrothermal activity due to interaction with the underlying snow layer after PFD emplacement was possibly not forceful enough to breach the surface in these locations or that the activity had diminished since the eruption. The hottest fumarole observed reached a temperature of 377C, 5 km from the lava dome. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data will be used to characterise the two deposits and assess cooling rates and emplacement temperatures. Preliminary data show that the two areas with hottest fumarole temperatures do not correspond to the hottest areas of the deposits. This is the first time extensive direct temperature measurements of warm PFDs have been obtained at Bezymianny.
DE: 8400 VOLCANOLOGY
DE: 8485 Remote sensing of volcanoes
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting