利用连续GPS资料分析芦山7.0级地震区域地壳变形特征  

Analysis on Deformation Characteristics of the Regional Crust in Lushan M7.0 Earthquake by Continuous GPS Observation Data

作　　者：丁晓光[1,2] 闫伟[3] 张艺[1] 苏利娜[1,2] 张永奇[1] 

机构地区：[1]陕西省地震局,陕西西安710068 [2]中国地震局地质研究所,北京100029 [3]中国地震台网中心,北京100045

出　　处：《灾害学》2015年第1期56-62,共7页Journal of Catastrophology

基　　金：国家"十二五"科技支撑计划(2012BAK19B02);中国地震局地震行业专项(201208009-13)

摘　　要：2013年4月20日,龙门山断裂带南段四川芦山附近发生7.0级地震,造成较严重地震灾害及其次生灾害。为研究地震区域地壳变形特征,利用芦山地震震中周边陆态网GPS连续站2010-2013年的观测资料,得到发震区域水平运动速度场和垂直形变场,获得距震中较近站点的同震位移;利用站间基线时间序列和应变参数时间序列得到了区域应变积累背景,并结合块体运动信息分离方法,进一步分析了震前可能存在的异常形变信息。从中得知:芦山地震发震区域处于块体挤出的"分流"地带,地壳水平变形量较小。站间基线QHBM-SCSN和QHBM-SCXJ在2012年下半年均出现偏离原有运动速率的趋势。SCXJ站时间序列信息分离结果显示,其N向和E向应变贡献分量在2012年也有曲线转折现象。In April 20th,201 3,an earthquake attacked the region of Lushan,Sichuan province in the south-ern Longmen mountains fault zone,and caused serious earthquake disaster and secondary hazards.In order to re-search the seismic crustal deformation characteristics,GPS continuous data in 201 0 -201 3 from the CMONOC a-round the epicenter of Lushan earthquake is used,the regional horizontal velocity and vertical deformation are cal-culated,and the coseismic displacement of the station near the epicenter is obtained.Based on the station baselines and strain parameter time series,the regional crustal deformation and strain accumulation background are re-searched;further analysis with the block information separation method shown that the abnormal deformation may exist before the earthquake.The main results got in this paper include：the earthquake region is in the block extru-sion “shunt”zone,and the crustal horizontal movement is small.In the second half of 201 2,a trend of deviation from the original motion was shown by the baseline of QHBM-SCSN and QHBM-SCXJ.Results of deformation sepa-rated from the time series of SCXJ station also showed that,the N and E component of the internal strain contribu-tion had a curve-transition phenomenon.

关 键 词：芦山7.0级地震 连续GPS数据 地壳运动 应变 时间序列 

分 类 号：P315.725[天文地球—地震学] X4[天文地球—固体地球物理学]