R. Wessels, Alaska Volcano Observatory, USGS Alaska Science Center, Anchorage, AK
S. Senyukov, Kamchatkan Experimental-Methodical Seismological Department, Geophysical Service Russian Academy of Science, Petropavlovsk-Kamchatsky, Russia
A. Tranbenkova, Institute of Volcanology and Seismology, Far East Division Russian Academy of Science, Petropavlovsk-Kamchatsky, Russia
M. Ramsey, Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, PA
D. Schneider, Alaska Volcano Observatory, USGS Alaska Science Center, Anchorage, AK
The Alaska Volcano Observatory (AVO) and the Kamchatkan Volcanic Eruption Response Team (KVERT) monitor the eruptive state of volcanoes throughout the Aleutian, Kamchatkan, and Kurile arcs. This is accomplished in part by analyzing thermal infrared (TIR) data from the Advanced Very High Resolution Radiometer (AVHRR) and Moderate-resolution Imaging Spectroradiometer (MODIS) sensors at least twice per day for major thermal anomalies. The AVHRR and MODIS 1 km spatial resolution data have been very useful for detecting large and/or high-temperature thermal signatures such as Strombolian activity as well as lava and pyroclastic flows. Such anomalies commonly indicate a major eruptive event is in progress. However, in order to observe and quantify small and/or lower temperature thermal features such as fumaroles and lava domes, higher spatial resolution data with better radiometric and spectral resolution are required.
We have analyzed > 2600 available night and day time TIR scenes acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) over the volcanoes of the northern Pacific. The current archive spans from March, 2000 to present. ASTER is the only instrument that routinely acquires high spatial resolution (30 - 90 m) night time data over volcanic targets. These data sets typically contain 5 TIR (8-12 microns) with 90 meter spatial resolution and 6 shortwave infrared (SWIR) bands (1-3 microns) with 30 meter spatial resolution. After the general survey of the volcanic arcs, we have focused our efforts on several targets. Mt. Hague, in the Emmons Lake complex on the Alaska Peninsula, has had over twenty mostly cloud-free ASTER observations since August 2000. A small lake in the lower crater of Mt. Hague has had a history of appearing and disappearing over the last few years. The ASTER data combined with several recent field observations allow us to track the changes in lake area and associated temperatures. With more frequent observations, we hope to determine the mechanism of these changes. The 1975-76 craters and lava flows of New Tolbachik Volcano in central Kamchatka appear as persistent thermal features in clear night time ASTER TIR data. The anomalies at the craters are likely caused by active fumaroles with 2003 field temperatures > 300C. Mutnovsky and Gorely Volcanoes in southern Kamchatka also have several persistent thermal features in the ASTER data from late 2001 until at least November 2003. These features correlate to a vigorous fumarole field and crater lakes. The Mutnovsky thermal features were also observed in AVHRR data by KVERT in March, June, and July 2003.
The goal of this work is the better detect changes in current volcano activity or precursors to new activity. Our ongoing survey of the ASTER TIR data has created a database of many small (<90 m) or low temperature (20 - 380C) thermal features at several volcanoes in the northern Pacific region. We will attempt to observe each of the identified features at least annually using ASTER data as it becomes available over each target.
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Submitted: American Geophysical Union Fall Meeting
Date: December 13 - 17, 2004