Observing Near-Real-Time Volcanoes Deformation Using InSAR – Time Series of LiCSBAS in Indonesia

Abstract

The Synthetic Aperture Radar (SAR) sensors onboard satellites are leading in advance to monitor physical changes of volcano edifices such as deformation. A few days of temporal resolution imageries provided by Sentinel-1 SAR make it possible to monitor volcanoes worldwide in near-real-time monitoring. The Sentinel-1 constellation produces a large amount of SAR images valuable for monitoring volcano deformation and hazard mitigation. However, processing the Interferometric SAR (InSAR) for a large SAR dataset is time-consuming and requires high-performance computers. Overcoming the problem, the Center for Observation & Modelling of Earthquakes, Volcanoes & Tectonics (COMET) created a program called Looking Inside the Continents from Space of Sentinel Aperture Radar (LiCSAR) integrated to InSAR time-series analysis of LiCSBAS InSAR to process and calculate the interferogram deformation in time series efficiently. This study presents the LiCSBAS observation for volcanic activities at Mts. Sinabung and Agung in North Sumatra and Bali, respectively. We have observed the activities of both volcanoes from 2015 to 2022. We have analyzed 1824 and 848 interferograms of Mt. Sinabung and Mt. Agung, respectively. The LiCSBAS InSAR time-series analysis was successfully processed for Mts. Sinabung and Agung despite being located under tropics. Velocity deformation of Mt. Sinabung is dominated by uplift around the summit, consistent with measurement by the Center for Volcanology and Geological Hazard Mitigation (CVGHM). In the period of January to March 2017, the lava dome measurement using laser distance meter showed an increase from 1.2 Mm3 to 1.7 Mm3, while LiCSBAS detected an uplift movement of 14 mm. On the contrary, the deformation of Mt. Agung at the summit of lava dome is 3 mm/yr indicate uplift, while subsidence is observed around the crater.