Abstract
Bezymianny (55.98°N, 160.59°E) is a Holocene andesitic composite volcano with a summit elevation of approximately 2,900 m and is located on the Kamchatka Peninsula, eastern Russia. Previously inactive for about 1,000 years, Bezymianny reactivated in 1955, culminating in a cataclysmic eruption on 30 March 1956. This directed blast generated a 1.3 km (north–south) by 2.8 km (east–west) horseshoe shaped crater opening to the east, similar in morphology and activity to Mt. St. Helens (USA). During the last 30 years Bezymianny has been regularly active, erupting one to two times per year on average. This work focuses on field-based and remote sensing observations of explosive eruptions and their products at Bezymianny, concentrating on the pyroclastic flow (PF) deposits on the southeast flank. The events of March 2000, January 2005, December 2006, May 2007 and October 2007 were focused on to elucidate information on the pyroclastic flow (PF) deposits that were emplaced. Two principal themes were addressed: (1) A thermal infrared (TIR) investigation of the eruptive events and products. This encompassed ground-based field work, Forward Looking Infrared Radiometer (FLIR) image data, and spaceborne data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). (2) A micrometer-scale textural investigation of vesicular block and ash samples collected in the field on the pyroclastic flow deposits. Scanning Electron Microscope (SEM) images were used to generate micron-scale digital elevation models (DEM) for the surfaces of each volcanic sample collected. These were compared to TIR emission spectra that were deconvolved to estimate surface vesicularity. This work demonstrates the utility of TIR observations from satellite, aerial, and ground-based data that, in combination with standard geological mapping, provide timely, accurate, and quantitative remote sensing data to assist in the prediction and monitoring of explosive volcanoes.
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