Surface textures and dynamics of the 2005 lava dome at Shiveluch Volcano, Kamchatka

Shiveluch is one of the largest and most active andesitic volcanoes of the Kuril-Kamchatka arc. It commonly alternates between Vulcanian explosive eruptions and periods of dome growth and subsequent dome collapse-driven block-and-ash flows. The volcano was in an extended period of heightened activity for most of the period 2004–2010. We examined this activity in detail using thermal infrared (TIR) remote sensing as part of the urgent request protocol (URP) program of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument and confirmed the results with ground-based photography and airborne TIR camera data. High-spatial-resolution TIR images were collected during both daytime and nighttime satellite overpasses prior to and following the large explosive event/eruption of 27 February 2005 and the dome growth that followed. During a field campaign in August 2005, a helicopter overflight designed to acquire visible and TIR data of the active dome was performed. This was a nadir-looking, low-altitude overflight and the first ever of Shiveluch volcano involving non-Russian scientists. The image data revealed an active crease structure in the center of the dome with a distinctly different, crescent shaped, high-temperature (>380 °C) zone roughly perpendicular to the crease. In order to provide a time context and estimate extrusion rates, the airborne data were compared to the spaceborne ASTER data and long distance ground-based photography of the dome acquired by our Russian colleagues. The presence of a crease structure and the complex thermal pattern on the surface were both unexpected discoveries that reveal the way in which exogenous dome growth was occurring at the time. This highly active period at Shiveluch provides a unique example to better understand silicic lava dome growth using TIR data. The results also demonstrate a straightforward approach for fusing ground, air, and spaceborne image data, which could be applied to other active domes around the world.