HR: 11:20h
AN: T32B-05    [Abstracts]
TI: Coseismic Strike-Slip Offsets of Surface Rupture Produced by 2001 Mw 7.8 Kunlun (Tibet) Earthquake, Measured From High-Resolution IKONOS Imagery and Field
AU: * Lin, A
EM: slin@ipc.shizuoka.ac.jp
AU: Nishikawa, M
EM: aiming777@hotmail.com
AB: The magnitude Mw 7.8 (Ms 8.1) Central Kunlun, earthquake occurred on 14 November 2001, in the Kunlun mountain area, north Tibet, and produced extensive surface rupturing over a distance of >400 km along the pre-existing Kunlun fault zone (Lin et al., 2002, 2003). The deformation characteristics and strike-slip displacement distribution of the coseismic surface rupture zone revealed by field investigation, seismic data, and satellite images have been described in a series of previous papers by ourselves and other groups. However, there are some conflicts on the amounts of strike-slip offsets reported by these groups. We demonstrated that large coseismic strike-slip offsets of >10 m and up to 16.3 m occurred in several locations by our filed observations (Lin et al., 2002, 2003), but other groups (e.g. Xu et al., 2002) showed no offset amounts over 10 m. Such differences in the field-measured offset amounts might be caused by the different measurement methods and the lake of field data due to the remote high mountain region and bed weather in the study area where is too difficult to access and to work long time in site. In this study, we focus our attention on the coseismic strike-slip offsets of the 2001 surface rupture by using high-resolution IKONOS and QUICKBIRD images and compare the analytical results from the images with the field data. Analyses and interpretations of 1m-resolution IKONOS, and 0.6m-resolution QUICKBIRD images reveal that the 2001 coseismic strike-slip offsets measured from IKONOS images range from 2 m up to 16.7 m, generally 3-8 m, which are generally consistent with those measured immediately in the field after the earthquake. The coseismic surface ruptures along which offsets were observed are mainly composed of a numerous of en echelon shear faults and cracks which are concentrated in a deformation zone ranging from a few meters up to ~500 m in width. The offsets measured along individual shear faults or cracks are typically 2-7 m, but up to >10 m in several locations. Our results show that high resolution remote sensing imagery provides a powerful tool for measuring coseismic strike-slip offsets and detecting ground deformation produced by large earthquakes in the remote and high mountain Tibet region.
DE: 0933 Remote sensing
DE: 1734 Seismology
DE: 1744 Tectonophysics
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
DE: 8100 TECTONOPHYSICS
SC: Tectonophysics [T]
MN: Fall Meeting 2005