Tracking the areas and volumes of pyroclastic flows at Semeru volcano during the 2021-2022 activity

Semeru volcano is one of the most active Indonesian volcanoes. Since 2014, the activity was dominated by small to moderate Vulcanian explosions from the summit. On Saturday 4th December 2021, the activity becomes more explosive with the emission of an ash plume of 15 km high and several pyroclastic density currents and lahars reaching up to 13 km from the summit (Global Volcanism Program, 2022). This explosive event killed about 50 people and destroyed surrounding villages causing the relocation of thousand inhabitants. The mapping and the estimation of pyroclastic flows are crucial to improve the risk assessment of future eruptions.

The aim of the project is to use a combination of high-resolution radar images (TerraSAR-X, PAZ) to derive information about the extend and the volumes of pyroclastic flows. Firstly, we will use amplitude and coherence images to map the outline of the pyroclastic flows (Poland, 2022). In addition, we will use bi-static radar interferometry with TanDEM-X datasets to map the topographic changes caused by the volcanic activity (e.g., Poland, 2014 ; Albino et al., 2015, 2020 ; Kubanek et al., 2015, 2021 ; Gremion et al., 2023). It will provide relevant information about the thicknesses and eventually the volume of the different flows emplaced since 2021.

To process the radar images, we will use the NSBAS processing chain currently developed at ISTerre (Doin et al., 2011) and we will adapt it to the high-resolution images. The objective is to develop a processing flowchart to produce routinely these outputs (e.g., maps of flow areas and topographic changes). Such pilot study could be relevant for the “Service National d’Observation” ISDeform that is in charge of the distribution of added-value products derived from satellite datasets to the scientific community in response to natural hazards in the French territory. Developments carried out at Semeru volcano could be applied in the case of a volcanic crisis in overseas active volcanoes such as Montagne Pelée or La Soufrière.

References

Albino, F., Biggs, J., Escobar-Wolf, R., Naismith, A., Watson, M., Phillips, J. C., & Marroquin, G. C. (2020). Using TanDEM-X to measure pyroclastic flow source location, thickness and volume : Application to the 3rd June 2018 eruption of Fuego volcano, Guatemala. Journal of Volcanology and Geothermal Research, 406, 107063.

Albino, F., Smets, B., d’Oreye, N., & Kervyn, F. (2015). High‐resolution TanDEM‐X DEM : An accurate method to estimate lava flow volumes at Nyamulagira Volcano (DR Congo). Journal of Geophysical Research : Solid Earth, 120(6), 4189-4207.

Doin, M. P., Guillaso, S., Jolivet, R., Lasserre, C., Lodge, F., Ducret, G., & Grandin, R. (2011, September). Presentation of the small baseline NSBAS processing chain on a case example : The Etna deformation monitoring from 2003 to 2010 using Envisat data. In Proceedings of the Fringe symposium (pp. 3434-3437). Frascati, Italy : ESA SP‐697.

Grémion, S., Pinel, V., Shreve, T., Beauducel, F., Putra, R., Solikhin, A., ... & Humaida, H. (2023). Tracking the evolution of the summit lava dome of Merapi volcano between 2018 and 2019 using DEMs derived from TanDEM-X and Pléiades data. Journal of Volcanology and Geothermal Research, 433, 107732

Kubanek, J., Westerhaus, M., Schenk, A., Aisyah, N., Brotopuspito, K. S., & Heck, B. (2015). Volumetric change quantification of the 2010 Merapi eruption using TanDEM-X InSAR. Remote Sensing of Environment, 164, 16-25.

Kubanek, J., Poland, M. P., & Biggs, J. (2021). Applications of bistatic radar to volcano topography—a review of ten years of TanDEM-X. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 14, 3282-3302.

Poland, M. P. (2014). Time‐averaged discharge rate of subaerial lava at Kīlauea Volcano, Hawai ‘i, measured from TanDEM‐X interferometry : Implications for magma supply and storage during 2011–2013. Journal of Geophysical Research : Solid Earth, 119(7), 5464-5481.

Poland, M. P. (2022). Synthetic aperture radar volcanic flow maps (SAR VFMs) : a simple method for rapid identification and mapping of volcanic mass flows. Bulletin of Volcanology, 84(3), 1-11.