Abstract: There are two earthquakes in Gaize on Jan 9(M_S 6.9)and Jan 16,2008(M_S 6.0).The two earthquakes were selected as examples to obtain the co-seismic deformation field with the 2-pass differential interferometric processing method.The results show that the earthquake faults locate near the tip of the Yibuchaka-Riganpeicuo Fault,and both seismic faults are normal faults;The seismogenic fault of the main shock strikes about N30癊 and that of the aftershock strikes about N21癊;There is evidence of surface rupture along the mainshock's causative fault,but no surface rupture has been observed on the aftershock fault;The co-seismic deformation field is about 30km in length and 20km in width;The maximum displacement in LOS of the hanging wall of the main-shock fault is 39.2cm,and that of footwall is 11.2cm,the relative dislocation between them is 50.4cm;The displacement caused by the aftershock is 9.4cm(LOS).

Key words: D-InSAR, Gaize earthquake, coseismic deformation

摘要： 针对2008年1月9日M_W6.4西藏改则地震和2008年1月16日的M_W5.9余震,通过两通(2-pass)加外部DEM差分干涉处理技术(D-InSAR),提取了地震区域2次地震累积的视线向(LOS)同震形变场。结果表明:发震断层均为正断层,位于依布茶卡-日干配错断裂端点附近。主震发震断层走向为N30°E,余震发震断层走向为N21°E,两断层距离约7km;在影像上主震发震断层有造成地表破裂的痕迹,余震未见地表破裂的痕迹;这次地震造成的同震形变场长约30km,宽约20km,主震断层上盘和下盘视线向最大形变量分别为39.2cm和11.2cm,两盘相对位错达50.4cm,余震造成的视线向形变量为9.4cm。

关键词: 差分干涉测量, 改则地震, 同震形变场