Abstract
The estimation of the volume of volcanic flows during an ongoing eruption is challenging but this information is crucial for improving risk assessment and for forecasting future events. Although previous studies have shown the ability of TanDEM-X satellite data to derive the thickness and the volume of lava flow fields during effusive eruptions, the method has not been explored yet for pyroclastic flows. Using bi-static interferometry, we produce TanDEM-X DEM on Fuego volcano (Guatemala) to measure the significant topographic changes caused by the 3rd June 2018 eruption, which destroyed the town of San Miguel Los Lotes. We estimate the volume of the Pyroclastic Density Currents (PDCs) to be 15.1 ± 4.2 × 106 m3. The deposits are likely to be the source of lahars during future rainy seasons. We identify the main channel of deposition (positive elevation changes) and the source region of pyroclastic material, areas of significant substrate erosion, and vegetation destruction (negative elevation changes). Our results show that the June 3rd 2018 pyroclastic flow was predominantly composed of material which had gravitationally collapsed from a location close to the vent. The eroded material increased the volume of the flow (bulking) and likely caused the run-out distance of the 2018 PDC to be larger than previous eruptions (1999–2017). This study highlights the potential of remote sensing techniques for actively monitoring topography changes in inaccessible locations and to rapidly derive deposit volumes.
Highlights
The mapping of volcanic flows (e.g. lava flows, pyroclastic density currents (PDC), lahars) during and after an eruption is essential for forecasting future volcanic behaviour and for refining existing hazard maps, both of which contribute to reducing exposure to risk
We analyse the distribution of positive and negative topographic changes associated with the 2018 Pyroclastic Density Currents (PDCs), and we discuss the implications for estimates of deposit volumes and source mechanisms
For the intermediate and distal sections of the 2018 PDCs, no topographic changes are associated with the 2015 October eruption (Fig. 2a), so we will only evaluate the DEM difference occurring between 29 October 2015 and 06 June 2018
Summary
The mapping of volcanic flows (e.g. lava flows, pyroclastic density currents (PDC), lahars) during and after an eruption is essential for forecasting future volcanic behaviour and for refining existing hazard maps, both of which contribute to reducing exposure to risk. Satellite InSAR is most often used to measure small (centimetre to meter scale) surface deformation, it can be used to produce DEMs or maps of large-scale (meters to 10s of meters) topographic changes, and is functional both day and night and in all weather conditions For this reason, InSAR has been widely applied for studying recent lava flow fields in both repeat-pass (Lu et al, 2003; Rowland et al, 2003; Ebmeier et al, 2012) and bistatic/single-pass modes (Poland, 2014; Albino et al, 2015; Kubanek et al, 2015; Richter et al, 2016; Arnold et al, 2017; Dirscherl and Rossi, 2018; Lundgren et al, 2019). We analyse the distribution of positive and negative topographic changes associated with the 2018 PDCs, and we discuss the implications for estimates of deposit volumes and source mechanisms
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
