Deformation of 921 Earthquake by Satellite Radar Interferometry: Co-seismic and Post-seismic Estimation

雷達影像干涉於921同震與震後變形觀測

梁隆鑫(L. S. Liang) ； 王志添(C. T. Wang) ； 陳錕山(K. S. Chen) ； 蔡義本(Y. B. Tsai) ； 陳哲俊(A. J. Chen)

《航測及遙測學刊》 11卷3期 (2006/09) Pp. 327-336

https://doi.org/10.6574/JPRS.2006.11(3).8

摘要

1999年9月21日1時47分，在台灣中部南投縣發生了芮式規模7.3的強烈地震，震央位於日月潭西北方約12.5公里的集集鎮上，震源深度8公里，此次地震後的第一週死亡人數就超過2,100人。在這篇研究裡，我們利用八幅不同日期(1998/01/01、1999/01/21、1999/05/06、1999/06/10、1999/07/15、1999/09/23、1999/10/28、2000/01/06)的ERS雷達影像差分干涉，監看其震後變形現象，結果顯示在車籠浦斷層東側的新社鄉，由(1999/10/28-1999/09/23)這組資料看到的變化量是5.6公分，由(2000/01/06-1999/10/28)看到的變化量是3公分，可能原因是震後重力或彈性回跳所造成，不過需要再進一步研究查證。

關鍵字

合成口徑雷達影像 ； 差分干涉 ； 地震

並列摘要

A major earthquake (M(superscript L)=7.3) occurred near the small town Chi-Chi in the Nantou County, Taiwan, at 1:47 a.m. local time on September 21, 1999 (17:47 GMT on 20 September). The epicenter was 12.5 km northwest the Sun-Moon lake. The focal depth is 8 km. The death toll had exceeded 2100 and was mounting during the first week after the main shock. In this study, we mainly focus on the numerous aftershocks; some of which reach magnitudes of M(superscript L)=6.8. In this paper we used 8 scenes (1998/01/01, 1999/01/21, 1999/05/06, 1999/06/10, 1999/07/15, 1999/09/23, 1999/10/28, and 2000/01/06) of ERS2 images and an external DEM data, by the means of two passes SAR differential interferometry, to detect the deformations before and after the Chi-Chi earthquake. The results based on the available image sets show that prior to the earthquake, it has no clear deformation signature in the interferogram and there are slight displacements in the east of Chelungpu fault; and the displacement areas of the two pairs of DINSAR (1999/10/28-1999/09/23; 2000/01/06-1999/10/28) were at the same place. The former had about 5.6 cm deformation in slant range, while the latter was about 3 cm. These post-seismic deformations may be due to gravity effects, or the theory of elastic rebound.

並列關鍵字

SAR ； Interferometry ； Earthquake