Natural Hazards and Earth System Sciences (2015-03-01)

Estimation of three-dimensional crustal movements in the 2011 Tohoku-Oki, Japan, earthquake from TerraSAR-X intensity images

  • W. Liu,
  • F. Yamazaki,
  • M. Matsuoka,
  • T. Nonaka,
  • T. Sasagawa

DOI
https://doi.org/10.5194/nhess-15-637-2015
Journal volume & issue
Vol. 15, no. 3
pp. 637 – 645

Abstract

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The Tohoku-Oki earthquake on 11 March 2011 caused significant widespread crustal movements. In a previous study, we proposed a method for capturing two-dimensional (2-D) surface displacements from a pair of pre- and post-event TerraSAR-X (TSX) intensity images. However, it is impossible to detect three-dimensional (3-D) displacements from one pair of TSX images. In this study, three pairs of pre- and post-event TSX images taken on different paths were used to estimate 3-D crustal movements. The relationship between the actual 3-D displacements and the converted 2-D movements in the synthetic-aperture radar (SAR) images was derived based on the observation model of a SAR sensor. The 3-D movements were then calculated from three sets of detected 2-D movements that occurred within a short time period. Compared with GPS observations, the proposed method was found to be capable of detecting the 3-D crustal movements with sub-pixel accuracy.