Space-based monitoring of the 2015 eruption of Villarrica Volcano, Chile

Abstract

Many volcanoes in the world are located in remote areas, which are in most cases not accessible during volcanic eruptions. Satellite-based Earth Observation (EO) provides a non-restrictive global monitoring of all sub-aerial volcanoes. As a case study, we will present the analysis of the 3 March 2015 eruption of Villarrica Volcano, Chile. This eruption was investigated based on a time series analysis of thermal data acquired by the small experimental German Aerospace Center (DLR) satellite Technology Experiment Carrier-1 (TET-1). We will present a newly developed workflow for an atmospheric correction of the thermal satellite imagery and an analysis of the detected thermal hotspots at sub-pixel level, including their temperature, area coverage, and radiant power. The detected thermal anomalies were compared with observations derived from Moderate Resolution Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS) data. Nine days before the eruption thermal hotspots were detected. After the decrease of the radiant power following the 3 March 2015 eruption, a stronger increase of the radiant power was observed on 25 April 2015. Moreover, the eruption-related ash coverage of the glacier at Villarrica Volcano was investigated by TET-1 imagery.