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Up-to-date information on the outline, volume and effusion rate during an effusive volcanic eruption is crucial as it is a major controlling factor of the lava flow lengths, the prospective duration and hence the associated hazards. Here, we present a multi-sensor approach combining thermal and topographic satellite data for estimating lava effusion rates and volume. We investigated the large 2021 volcanic eruption at Cumbre Vieja, La Palma and we combined MODIS and VIIRS thermal data-based effusion rate estimates with digital surface model (DSM) analysis derived from bi-static TanDEM-X synthetic aperture radar (SAR) and optical-tri-stereo Pléiades data. Advantage of this multi-sensor approach is to achieve both, high-frequent observation of the relative short-term effusion rate trends and precise total volume estimates. Our results show a final subaerial lava volume of 212x106 ± 13x106 m³with a mean output rate (MOR) of 28.8±1.4 m³/s. The 2021 Cumbre Vieja eruption was characterized by an initially sharp eruption rate peak, followed by a gradually decreasing trend, and interrupted by two short-lived peaks in mid and in end November. Comparison with independent seismic observations show a high eruption rate accompanied by weak seismicity during the early stages of the eruption, while during later stage the lava effusion trend coincides with seismicity. We will demonstrate that the geophysical monitoring of eruption rate fluctuations allows to speculate about changes of an underlying pathway during the 2021 Cumbre Vieja eruption., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

The 2022 hydrological drought in Europe was a significant event that resulted in widespread water shortages and economic disruption. The low water levels had significant implications for supply chains, transport capacity and water quality. In this study, we used a fully automated, neural-network based processing chain to semantically segment Sentinel-2 data. The processing chain was originally developed for flood detection. To map changes in surface-water extent during the drought, we compared reference water masks of the previous two years with the extent of summer 2022.Our results show that the drought had a measurable impact on surface-water extents across Germany, with many rivers and lakes experiencing declines. A decline can be observed in all river basins. By providing detailed maps of these changes, our study offers valuable insights into the impact of droughts on surface water extent and can help inform future drought mitigation and management efforts in the region. The results presented in this contribution indicate, that the surface water extent in Germany 2022 declined by 3.1% compared to the previous two years. The most affected hydrological catchment area was the Weser river basin, which experienced a water extent loss of 7.4%.

Villarrica Volcano is one of the most active volcanoes in the South Andes Volcanic Zone. This article presents the results of a monitoring of the time before and after the 3 March 2015 eruption by analyzing nine satellite images acquired by the Technology Experiment Carrier-1 (TET-1), a small experimental German Aerospace Center (DLR) satellite. An atmospheric correction of the TET-1 data is presented, based on the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Emissivity Database (GDEM) and Moderate Resolution Imaging Spectroradiometer (MODIS) water vapor data with the shortest temporal baseline to the TET-1 acquisitions. Next, the temperature, area coverage, and radiant power of the detected thermal hotspots were derived at subpixel level and compared with observations derived from MODIS and Visible Infrared Imaging Radiometer Suite (VIIRS) data. Thermal anomalies were detected nine days before the eruption. 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. In addition, we show that the eruption-related ash coverage of the glacier at Villarrica Volcano could clearly be detected in TET-1 imagery. Landsat-8 imagery was analyzed for comparison. The information extracted from the TET-1 thermal data is thought be used in future to support and complement ground-based observations of active volcanoes.