Thermal Analysis of Volcanoes Based on 10 Years of ASTER Data on Mt. Etna

Abstract

The EOS-1 Terra ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) has acquired about 200 images (100 of them sufficiently cloud-free to be used) over Mt. Etna since 1999. This chapter shows the results from the analysis of 10 years Mt Etna activity using thermal infrared (TIR) high spatial resolution data by a semi-automatic procedure that extracts radiance values of the summit area with the goal of detecting variation related to eruptive events. Night time data showed a good correlation with the main eruptive events that occurred both in the summit and in the flank areas. A comparison of the variance of maximum ASTER TIR radiance with variance of the maximum AVHRR TIR radiance (Advanced Very High Resolution Radiometer) for the same area confirms good correlation in terms of trend and values between the two data sets. Finally this study emphasizes the importance of high spatial resolution TIR data during background monitoring to detect changes in the thermal emission that may be related to an impending eruption and the need to further improve the spatial resolution in the TIR channels to better separate the thermal active areas in volcanic systems.