Three-dimensional surface displacement map of the 2008 Wenchuan earthquake derived from Phase Correlation (PC) sub-pixel offset method and Adaptive Local Kriging (alk) DInSAR data

摘要

Differential Interferometric Synthetic Aperture Radar (DInSAR) is an effective technique to measures the surface displacement caused by strong earthquakes, such as the 2008 Wenchuan earthquake in China. However, in the area subject to the most significant deformation along the Longmenshan fault zone, the coherence between pre- and after- earthquake SAR images is completely lost because of the earthquake induced violent and chaotic destruction on the land surface and consequently, no surface displacement data can be measured. The missing data were recovered using Adaptive Local Kriging (ALK) method to produce a complete Line Of Sight (LOS) displacement map. As a further step to characterize the 3D (three-dimensional) co-seismic deformation, horizontal displacement maps were generated using the Phase Correlation based Image Analysis System (PCIAS), and in combination with the ALK DInSAR data, the vertical displacement map can then be decomposed. Thus, a 3D displacement dataset is accomplished. This dataset shows the thrust and right-lateral strike slip motions along the Longmenshan fault system with two major uplift in Yingxiu and Beichuan areas respectively.