Analysis of the 4 December 2021 lahar on Mount Semeru using remote sensing data.
Samuel McGowan1 , Jonathan Procter1, Stuart Mead1, Gabor Kereszturi1, Ian Hamling2, Geoff Kilgour3, Fabien Albino^4 ^
Affiliations: 1Volcanic Risk Solutions, Massey University, Palmerston North , New Zealand; 2GNS Science Te Pu Ao, Lower Hutt, New Zealand; 3GNS Science Te Pu Ao, Taupo, New Zealand; 4Institut des Sciences de la Terre (ISTerre), University Grenoble Alpes, Grenoble, France;
Presentation type: Poster
Presentation time: Tuesday 16:30 - 18:30, Room Poster Hall
Poster Board Number: 158
Programme No: 3.5.17
Abstract
Mount Semeru in Indonesia is a prolific producers of lahars, driven by its ongoing volcanic activity and humid tropical climate. On December 4, 2021, an eruption triggered a dome collapse event. The combination of heavy precipitation and the remobilization of volcanic block-and-ash flow material resulted in the formation of a deadly lahar causing 51 fatalities and significant economic and agricultural damage in the southeastern portion of the ring plain. The combined application of radar and optical remote sensing allowed for an analysis of the laharic processes and resulting geomorphic change which provides invaluable information for improving modelling and hazard mitigation. Radar remote sensing enables the study of these processes in tropical environments where cloud coverage impedes optical and ground observations. This study combines observations from Sentinel-1 amplitude images and derived products with high resolution Planet surface reflectance images for calibration of interpretations. In parallel to amplitude images, rain fall accumulation data was integrated to focus on the triggering mechanisms of the lahar which would support future decision making and mitigate human losses.