关键词: SPOT影像, IKONOS影像, 地震破裂带, 宏观震中, 昆仑山口西8.1级地震

Abstract: On November 14,2001,an M_s 8.1 earthquake occurred in the west of Kunlunshan Pass. This event is the greatest earthquake that occurred in China continent following the Zayu-Medog,Xizang M_s8.6 earthquake of August 15,1950 and the Damxung,Xizang M_s 8.0 earthquake of November 18,1951. The earthquake occurred in Hoh Xil,a depopulated zone in the northern Qinghai-Xizang Plateau,where field investigation is very difficult to be carried out due to harsh climate and thin air. High spatial resolution satellite images are applicable to the interpretation of earthquake surface rupture zone. The 10m spatial resolution SPOT images may reveal distinctly the major rupture zone,while the 1m spatial resolution IKONOS images may display the fine structures and kinematical characteristics of the surface rupture. This paper presents the results of the study on the surface rupture of the west of Kunlunshan Pass earthquake by using SPOT and IKONOS images. The study shows that the surface rupture zone is located mainly along the abrupt variation zone of landforms on the alluvial-pluvial platform or the rear edge of the platform at the southern foot of the Kunlunshan Mountains. The surface rupture to the east of Buka Daban Peak is about 350km in length and striking 100°,consisting of 3 sub-rupture zones. This surface rupture is superimposed on the preexisting rupture zone. A series of gullies crossing the rupture zone have been offset left-laterally,and the average slip rate is estimated to be 13.4～16.8mm/a. The interpretation of the SPOT and IKONOS images demonstrate that the macroscopic epicenter of this earthquake should be at 93°17′E,35°47′N,in the vicinity of the Yuxifeng Peak,where the maximum left-lateral horizontal dislocation is 7.8m and the width of the surface rupture zone reaches up to 1250m. This conclusion is in good agreement with the location of macroscopic epicenter (93.3°E,35.8°N ) deduced by China Earthquake Administration for this earthquake.

Key words: SPOT images, IKONOS images, earthquake rupture zone, macroscopic epicenter, west of Kunlunshan Pass M_s 8.1 earthquake