Current Activity Characteristics of the Fault Zone Along the Northern Margin of West Qinling Range Revealed by GPS Measurement

作     者：Li Yanxing Hu Xinkang and Kang LaixunFirst Crustal Deformation Monitoring Center, CSB, Tianjin 300180, China Lanzhou Institute of Seismology, CSB, Lanzhou 730000, China 

作者机构：First Crustal Deformation Monitoring CenterCSBTianjin 300180China Lanzhou Institute of SeismologyCSBLanzhou 730000China 

出 版 物：《Earthquake Research in China》 (中国地震研究（英文版）)

年 卷 期：2000年第14卷第2期

页      面：6-15页

学科分类：070801[理学-固体地球物理学] 07[理学] 0708[理学-地球物理学] 

基　　金：This project was supported jointly by Satellite Application(94)No.1 Project D1 of Commission of Science Technology and Industry for National Defense and Project No 49572142 of National Science Foundation China 

主　　题：GPS measurement Fault activity characteristics Strain field analysis 

摘      要：The fault zone along the northern margin of West Qinling Range is a major active fault zone in the key seismic monitoring area in the southeastern part of Gansu Province. In order to study the current activity characteristics of this fault, GPS monitoring network has been arranged along both sides of the fault and 3 measurements have been made from 1996 to 1998. The result indicates that obvious differential movement exists along the north and south sides of the fault and the eastward movement on the south side is 3.8 mm/a larger than that on the north side. In the GPS network, the shortened side is generally in the trend of EW and the extended side is basically NW to SE. The principal compressional stress trend in this area is about EW and the sinistral motion is obvious in the eastern part of the fault (near Wushan). The measured results also indicate that the displacement rate has decreased by 50% and the compressional strain has increased by 100% as compared the data of 1997 -1998 with those of 1996-1997, which shows that the compressional stress field in this region is intensifying and the next earthquake might be developing at present.