Total Variation Regularization of Geodetically Constrained Block Models in Southwestern Taiwan
Date: 4/25/2019
Time: 10:45 AM
Room: Puget Sound
Plate convergence at more than 83 mm/yr makes Taiwan one of the most active tectonic regions in the world, as this strain is accommodated on a complex network strike-slip and thrust faulting. In this study, we use ascending and descending Interferometric Synthetic Aperture Radar (InSAR) data as well as CGPS measurements to reveal interseismic deformation in southwestern Taiwan. We combine InSAR and CGPS measurements from 2005-2010 and use the resulting deformation field to constrain a block model of interseismic crustal deformation. We use total variation regularization (TVR) to algorithmically assess the best-fitting block geometry based on the geodetic observations, simultaneously estimating block rotations and fault slip rates on block-bounding faults. The block model results imply that the margins of the Western Foothills accommodate most of the interseismic deformation in southwestern Taiwan. Geodetic observations show 20-40 mm/yr southwestward motion in the Pingtung plain in south Taiwan relative to west Taiwan that indicates tectonic escape due to plate collision, and more than 10 mm/yr uplift in the southern part of the Western Foothills. Our preferred grouped block model result suggests up to 4 cm/yr interseismic slip rate along the main detachment about 5-8 km below the Western Foothills, but most of the fault ramps are locked interseismically. Our approach shows an efficient and objective way to estimate fault activities and seismic hazards in the interseismic period based on dense geodetic measurements and their uncertainties.
Presenting Author: Mong-Han Huang
Authors
Mong-Han Huang mhhuang@umd.edu University of Maryland, College Park, Maryland, United States Presenting Author
Corresponding Author
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Eileen L Evans eileen.evans@csun.edu California State University, Northridge, Northridge, California, United States |
Total Variation Regularization of Geodetically Constrained Block Models in Southwestern Taiwan
Category
Advances in Tectonic Geodesy