GNSS约束下的甘孜-玉树-鲜水河断裂带滑动速率研究  

A Review on Slip Rate of the Ganzi-Yushu-Xianshuihe Fault Zone by GNSS Constraints

作　　者：王艺晨 郝明[2] 余中元 陈柏旭 WANG Yichen;HAO Ming;YU Zhongyuan;CHEN Baixu(Institute of Disaster Prevention,Sanhe 065201,Hebei,China;The Second Monitoring and Application Center,China Earthquake Administration,Xi'an 710054,Shaanxi,China)

机构地区：[1]防灾科技学院,河北三河065201 [2]中国地震局第二监测中心,陕西西安710054

出　　处：《地震研究》2025年第3期382-390,共9页Journal of Seismological Research

基　　金：第二次青藏高原综合科学考察研究子专题(2019QZKK0901);中国地震局地质研究所国家野外科学观测研究站(NORSLS23-05).

摘　　要：甘孜—玉树—鲜水河断裂带是青藏高原重要的大型边界走滑断裂,基于GNSS数据约束该断裂带的现今滑动速率有助于认识其活动习性,便于探讨其现今变形特征与模式。利用GNSS速度场横跨甘孜—玉树—鲜水河断裂带构建了7个速率剖面,获取该断裂带滑动速率变化。结果表明:该断裂带现今左旋滑动速率由NW向SE逐渐增大,其中,甘孜—玉树断裂走滑速率为4.9 mm/a,鲜水河断裂北西段走滑速率为9.5 mm/a,其东段的康定—石棉段滑动速率增加至10 mm/a,再向南至安宁河—则木河和大凉山断裂,剪切速率基本保持在10 mm/a左右。甘孜—玉树断裂水平缩短速率为2~4 mm/a,向东至鲜水河断裂和安宁河断裂水平缩短较弱,而大凉山断裂具有约为2 mm/a的地壳缩短变形,则木河断裂有约为1 mm/a的拉张速率。这一结果表明:甘孜—玉树—鲜水河断裂带的现今滑动速率远低于此前的认识,“连续变形”理论模型可能更适用于大陆内部的构造变形。The Ganzi-Yushu-Xianshuihe Fault Zone is an important large-scale boundary slip fault on the Tibetan Plateau.The present-day slip rate constraining this fault zone calculated according to GNSS data can help understand the fault zone's activity behaviour and explore the fault zone's present-day deformation characteristics and deformation patterns.On the basis of the GNSS velocity field,seven rate profiles across the Ganzi-Yushu-Xianshuihe Fault Zone are constructed,and main conclusions are as follows:The present-day,left-lateral,strike-slip rate of the Ganzi-Yushu-Xianshuihe Fault Zone gradually increases from Northwest direction towards Southeast direction.The Ganzi-Yushu Fault slips at the rate of 4.9 mm/a.The Northwest segment of the Xianshuihe Fault slips at the rate of 9.5 mm/a.The eastern segment of the Xianshuihe Fault,namely the Kangding-Shimian Fault,slips at a rate of 10 mm/a.In the Anninghe-Zemuhe Fault and the Daliangshan Fault,the shear rate is about 10 mm/a.Meanwhile,in the Ganzi-Yushu Fault,the Crust's shrinking rate is 2-4 mm/a.The Daliangshan Fault Zone undergoes crustal shrinking at the rate of about 2 mm/a,and the Zemuhe Fault has a tensile rate of about 1 mm/a.This reveals that the present-day slip rate of the Ganzi-Yushu-Xianshuihe Fault is much lower than the previous research results,and the theoretical model of“continuous deformation”may be more suitable for researching the tectonic deformation of the interior continent.

关 键 词：甘孜—玉树—鲜水河断裂带 GNSS数据 滑动速率 青藏高原 

分 类 号：P315.725[天文地球—地震学]