[U-02] Remote Sensing Role in Sustainable Development

[U02-03] Coseismic and postseismic deformation due to the 19 Jan 2020, Mw 6.0 Jiashi earthquake from InSAR and BOI measurements

*Yan Cui¹, Zhangfeng Ma², Yosuke Aoki¹, Jiaqing Wang¹, Lang Xu¹ (1.The university of Tokyo, 2.Nanyang Technological University)

Keywords:InSAR, Coseismic and postseismic deformation, Earthquake hazards

As one of the few large-scale compressional intracontinental orogenic belts in the world, the Tian Shan (TS) is a natural laboratory for understanding the Cenozoic orogenic processes driven by the India–Asia collision. On 19 January 2020, a Mw 6.0 event struck the Kalpin region, where the southern frontal TS interacts with the Tarim basin. An analysis of Interferometric Synthetic Aperture Radar (InSAR) and Burst Overlap Interferometry (BOI) reveals coseismic and postseismic (~2 years) surface displacements associated with this earthquake. The maximum and minimum line-of-sight displacements from the ascending orbit are 5.9 cm and -3.6 cm, respectively, and those from the descending orbit are 6.2 cm and -2.2 cm, respectively. The minimum along-track displacement from the ascending orbit is -6.6 cm and the maximum along-trace displacement from the descending orbit is 7.3 cm. We also found that the location of postseismic surface deformation is shifted southward from the coseismic displacements. InSAR and BOI data were jointly inverted for coseismic and postseismic slip on the Keping Thrust (KPT). Considering a realistic fault model, we parametrize non-planar fault geometry with a set of polynomial parameters that allow for down-dip variations in the KPT fault geometry. We use Bayesian inference to estimate the non-planar fault parameters from coseismic displacements, yielding an ensemble of plausible models that characterize the uncertainties of the non-planar fault geometry and the fault slip. The postseismic slip distribution is inverted using the inferred non-planar fault model as well.