SPOT和IKONOS影像在昆仑山口西8.1级地震中的应用研究  

APPLICATION OF SPOT AND IKONOS IMAGES TO THE STUDY OF THE WEST OF KUNLUNSHAN PASS EARTHQUAKE (M_S 8.1)

作　　者：单新建[1] 李建华[1] 马超[1] 

机构地区：[1]中国地震局地质研究所

出　　处：《地震地质》2005年第1期145-154,共10页Seismology and Geology

基　　金：科技部社会公益研究专项(2002DIA10001);国家自然科学基金(40374013)共同资助

摘　　要：昆仑山口西8.1级地震发生在青藏高原北部可可西里无人区,这里气候寒冷、空气稀薄,野外考察极其艰难.利用高分辨率卫星影像进行地震地表破裂带解译,10m分辨率SPOT卫星影像能够清楚地反映出地震地表破裂主破裂带的形迹;1m分辨率IKONOS影像,是一幅真实的地表微缩景观,形象、直观地反映出地震地表破裂的精细结构及运动特征.研究表明:昆仑山口西8.1级地震地表破裂带位于东昆仑断裂南麓冲洪积台地或冲洪积台地后缘的地貌陡变带,在布喀达坂峰以东的地表破裂带长近350km,由3条次级破裂组成,走向100°,是一条叠置在先存地震破裂带上的地震地表破裂带.流经破裂带的一系列沟谷发生左旋同步扭曲,平均滑动速率为13.4～16.8mm/a.宏观震中位于93°17′E,35°47′N玉西峰附近的地震破裂带上,这里最大地震位错为7.8m,地震破裂带最宽达1 250m,这与中国地震局推测的宏观震中93.3°E,35.8°N非常接近.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.

关 键 词：昆仑山口西8.1级地震 地震破裂 IKONOS影像 地震地表破裂带 宏观震中 滑动速率 青藏高原北部 无人区 野外考察 景观 

分 类 号：P315[天文地球—地震学] P316.244[天文地球—固体地球物理学]