[U-02] Remote Sensing Role in Sustainable Development

[U02-01] Four-dimensional Surface Deformations Capturing the Inflation of Sierra Negra Volcano, Galápagos, During 2018-2023

*Zhuang Gao^1,2、Yosuke Aoki²、Zhangfeng Ma^3,4、Xiufeng He¹ (1.School of Earth Sciences and Engineering, Hohai University、2.Earthquake Research Institute, The University of Tokyo、3.Asian School of the Environment, Nanyang Technological University, Singapore、4.Earth Observatory of Singapore, Singapore)

キーワード：InSAR, Volcano deformation, Sierra Negra, four-dimensional deformation

Sierra Negra, located in the western Galápagos Islands, is one of the most active volcanoes in the world. The most recent eruption, which occurred during 26 June–25 August 2018, induced meter-scale subsidence. Compared to the intense focus on this eruptive unrest, its post-eruptive deformation is poorly studied. This study investigates the post-eruptive deformation dynamics of Sierra Negra from 2018 to 2023 by employing interferometric synthetic aperture radar interferometry (InSAR) and continuous Global Navigation Satellite System (GNSS) measurements. We analyze both ascending and descending Sentinel-1 images with time series InSAR, Burst Overlap Interferometry (BOI), and Pixel Offset Tracking (POT) technologies to derive the deformation along both the line-of-sight and azimuth directions. On this basis, the 3-D (spatial) + 1D (temporal) post-eruptive displacement field, combined with GNSS observations, is reconstructed using the SM-VCE (strain model and variance component estimation) method. Furthermore, the evolution of the magma system through time is tracked. The results may provide more insights to the inflation behavior of Sierra Negra in the years following the 2018 eruption.