Abstract
The Mw 9.0 Tohoku Earthquake that occurred on March 11, 2011, off the Pacific coast of northeastern (Tohoku) Japan caused gigantic tsunamis, resulting in widespread devastation and crustal movements. In a previous study, we proposed a method for capturing the two-dimensional (2D) surface movements from pairs of temporal intensity images, based on the high orbit accuracy of the satellite TerraSAR-X (TSX). Detecting three-dimensional (3D) displacement from a single pair of TSX images is difficult, and thus in the present study we used three pairs of TSX images taken in the ascending and descending paths to estimate 3D crustal movements. First, the 2D crustal movements due to the 2011 Tohoku earthquake were detected from three respective pairs of images. We derived the relationship between the 3D displacement and the 2D converted movement in synthetic aperture radar (SAR) images according to the observation model and acquisition conditions of the SAR sensor. We then estimated the 3D movements by combining the detected 2D movements that occurred within a short time interval. We compared the results with the GEONET observation records and found that the results and records are consistent with each other.
