TerraSAR-X intensity images used to estimate crustal movement caused by the 2011 Tohoku earthquake

This paper presents a novel method to estimate significant crustal movement caused by the 2011 Tohoku earthquake. The method is based on the assumption that independent of the dramatic changes of the ground surface, still many unchanged areas, which we call unchanged-feature points, can be found. First, we use the SIFT algorithm to detect the unchanged-feature point candidates in pre- and post-event TerraSAR-X images. Then, a subpixel alignment procedure is used to obtain accurately matched point pairs. Finally, the unchanged-feature points are detected by eliminating unstable point pairs. The crustal movement of Sendai area is estimated by the proposed method. Compared with the GPS records, our method is found to be a more suitable tool to detect crustal movement at a sub-pixel level.