1. Coseismic Displacement Measurement of the 2010 El Mayor, Mexico Earthquake by Subpixel Correlation from Optical Satellite Images Masashi Matsuoka and Shinsuke Kodama AIST, Japan

4. The 2005 Pakistan Earthquake 2000/11/14 2005/10/27 ASTER images (resolution: 15 m) taken pre- and post-event images The Mw 7.6 earthquake struck Northern Pakistan and Kashmir on October 8, 2005. Avouac et al. (2006) R: Band3N G: Band2 B: Band1 R: Band3N G: Band2 B: Band1

5. Displacements from Pixel-offset of ASTER Images East-west ground displacement (white to the east, black to the west) Avouac et al. (2006) South-north ground displacement (white to the south, black to the north)

6. Disparity (Pixel-offset) Analysis

7. Calculation Flow 1. Tie points: are obtained from the optimal pixel pair selection, by searching sub-pixel by sub-pixel, at the position that yields the highest cross-correlation of the area of the local window between the slave (post-event) and the master (pre-event) images. > Interval: 10-pixel > Local window size: 31  31 pixels > Threshold of correlation coefficient: 0.7 2. Slave image coregistration: is carried out by the second degrees polynomial regression using the points, whose correlation coefficient is larger than 0.95, in the above selected tie points. 3. Disparity: can be calculated from the residual in the locations of original and coregistered pixels for x (east-west) and y (south-north) directions of slave image.

9. Pre- and Post-earthquake PRISM Images 2009/09/14 2010/05/02 Path: 542 (west) 10 km 10 km

10. ALOS/PRISM Capabilities (source: JAXA) OB1 OB2 DEM generation Ortho-rectification Pixel resolution: 2.5 m Subpixel accuracy: approx. quarter meter

11. Pre- and Post-earthquake ortho-rectified PRISM Mosaic Images before after

12. Displacements from Pixel-offset of PRISM Images east-west component south-north component The correlation images were obtained with a sliding 31×31 pixels correlation window and 10-pixel step. Spatial resolution of the correlation images is approximately 75 m. Decorrelation areas where the cross-correlation coefficient is lower than 0.7 are discarded and appear in white. right-lateral strike slip fault 10 km 10 km − + − +

13. Displacements from Pixel-offset of PRISM Images east-west component south-north component The correlation images were obtained with a sliding 31×31 pixels correlation window and 10-pixel step. Spatial resolution of the correlation images is approximately 75 m. Decorrelation areas where the cross-correlation coefficient is lower than 0.7 are discarded and appear in white. 10 km 10 km − + − +

14. East-west Component from PRISM Image Pixel-offset Six profiles, A-A’ to F-F’, run across the fault trace are selected. Displacements are positive toward the east. Slip vectors of the east-west component of ground displacement obtained by six profiles.

15. South-north Component from PRISM Image Pixel-offset Six profiles, A-A’ to F-F’, run across the fault trace are selected. Displacements are positive toward the south. Slip vectors of the south-north component of ground displacement obtained by six profiles.

16. Stacked Profiles East-west component South-north component It can be clear to recognize the discontinuity caused by the fault rupture and the maximum displacements of approximately 2 m and 1.5 m are measured in the east-west and south-north directions, respectively.

17. Comparison with Field Survey ( Geotechnical Earthquake Engineering Reconnaissance, GEER Association Report No. GEER-023) The extracted displacements from PRISM image correlation are comparable to field survey results.