基于跨断层测量的鲜水河断裂带现今活动特征及其与强震关系研究  

Current activity characteristics of Xianshuihe fault zone and its relationship with strong earthquakes based on fault-crossing measurements

作　　者：李腊月[1] 季灵运[2] 李玉江[3] 占伟[1] 

机构地区：[1]中国地震局第一监测中心,中国天津300180 [2]中国地震局第二监测中心,中国西安710054 [3]中国地震局地壳应力研究所,中国北京100085

出　　处：《地震学报》2016年第5期739-750,814,共12页Acta Seismologica Sinica

基　　金：科技部基础性工作专项(2015FY210400);中国地震局震情跟踪课题(2015010203;2016010207);中国地震局监测;预测;科研三结合课题(153304)共同资助

摘　　要：利用鲜水河断裂带30多年的跨断层观测资料,基于断层三维运动模型,采用主成分分析法,综合研究了鲜水河断裂带现今运动学特征及其与周边几次强震的关系.研究结果表明:鲜水河断裂带在观测期内(1982—2015年)以左旋走滑运动为主,各段落的活动速率都不相同,其中炉霍段、道孚段的活动速率大于乾宁段,乾宁段趋于闭锁状态;断层活动参数时间序列曲线具有较明显的线性运动特征,但在个别时段内会出现偏离直线的加速或转折变化.此外,断层三维活动参数的主成分分析结果显示,断层水平走滑量和水平张压量的主成分和综合指标在2001年、2006年、2010年和2012年分别出现趋势性转折和破趋势的异常变化,断层垂直升降量第一主成分在2013年也出现了相对小幅转折变化,这些异常变化可能与2001年昆仑山口西MS8.1、2008年汶川MS8.0、2010年玉树MS7.1和2013年芦山MS7.0等地震有关,属于这几次大震的前兆、同震或震后效应.This paper employed the fault-crossing deformation data about three decades（1982—2015）along the Xianshuihe fault zone to analyze fault activity characteristics and its relationship with adjacent strong earthquakes by using the three-dimensional movement model of fault and principal component analysis method.The preliminary results show that the Xianshuihe fault zone exhibits the left-lateral strike-slip features during the observation period（1982—2015）,and the fault activity is different along each segments,the activity rates of Luhuo and Daofu segments are greater than that of Qianning segment,the Qianning segment tends to be locked.The series of fault activity parameters have obviously linear movement characteristic in the observation period,but in individual period,they show accelerating or turning deviating from the straight line.In addition,the principal component analyses of fault activity parameters show that the principal components and composite indicator of the fault horizontal strike-slip cumulant and horizontal tensional or compressive cumulant change original trend or break the trend respectively in the years 2001,2006,2010and2012,and the first principal component of fault vertical activity cumulant changes a little in 2013.These anomalies may be related with the 2001 western Kunlunshan Pass MS8.1,2008 Wenchuan MS8.0,2010 Yushu MS7.1and 2013 Lushan MS7.0earthquakes,belonging to the precursor,coseismic or postseismic effects of these strong earthquakes,respectively.

关 键 词：鲜水河断裂带 跨断层测量 断层活动参数 主成分分析 地震前兆 

分 类 号：P315.725[天文地球—地震学]