Speaker: Ann Chen, Associate Professor, Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin
Host: Thorsten Becker
Title: Studying the earthquake cycle using InSAR and coral derived surface deformation observations
Abstract: The Solomon Islands lie in one of the world’s most active subduction zones, but its remote nature has limited the collection of high-quality surface deformation observations, which provide crucial information about earthquake cycles at the plate boundaries. In this study, we quantify surface deformation using spaceborne Interferometric Synthetic Aperture Radar (InSAR) and coral measurements. A new InSAR analysis method is designed to distinguish deformation signals from tropospheric noise based on stacking solutions derived from subsets of interferograms. InSAR results reveal up to -235.8 cm of line-of-sight (LOS) deformation during the 2007 Solomons Islands earthquake, as well as a LOS deformation rate decay from 26.4 to 5.9 cm/year within ~ 2 years after the earthquake. Using the coral sample, nearly two decades of vertical deformation history is reconstructed. This time series reveals an ~ 2.3 cm/year linear subsidence trend prior to the 2007 Solomons Island earthquake, 67 cm of uplift during, and ~ 50 cm subsidence in the 2.5 years following the earthquake. The temporal characteristics of postseismic deformation rate decay inferred from independent coral and InSAR data are consistent. Satellite and Coral Geodesy methods provide valuable information about the region’s tectonic activity and fill the existing knowledge gaps.
About Ann: Ann Chen has more than 15 years of experience in SAR/InSAR algorithm design for earth system science applications. In 2017, she joined the Department of Aerospace Engineering and Engineering Mechanics at The University of Texas at Austin. Since 2018, she has also served as a faculty member (by courtesy) in the Department of Geological Sciences at UT Austin. She currently leads the Radar Interferometry Group housed in the Center for Space Research. Her group focuses on the development of new satellites, and especially interferometric Synthetic Aperture Radar (InSAR) techniques, for studying natural and induced seismicity, groundwater resources, natural disasters, and permafrost hydrology and carbon storage. She is a senior member of IEEE, and a member of the NISAR Operations Science Team.