摘要
利用1999—2007、2009—2011年的流动GNSS观测资料和2010.5年以来的连续GNSS观测资料与处理结果,分析了2013年7月岷县漳县MS6.6地震区域水平形变场及其变化。获得的结果显示:①岷县漳县MS6.6地震发生在地壳运动的转折区域内,该区域运动量级较小、水平形变也相对较弱;②发震区带1999—2007年最大主应变为正负应变的过渡带,2009—2011年最小主应变也为正负应变的过渡带,1999—2007年则相对较大;③发震区带最大剪切应变相对较小,同时也是旋剪形变左、右旋的转化区;④连续站的结果显示该地震是在几乎纯逆冲构造活动背景下发生的,同震形变较小,其范围在距震中数十公里的半径内;⑤震前未发现GNSS观测结果中存在短临异常,但存在着趋势性形变亏损异常等。
Using the mobile GNSS observations of 1999--2007, 2007--1999, and continu- ous GNSS observations since 2010.5 and their processing results, horizontal deformation field and its changes before the Minxian--Zhangxian Ms6. 6 earthquake have been ana- lyzed. We found that （1） the Minxian--Zhangxian Ms6.6 earthquake occurred in the tran- sition area ofcrust movement, in which movement magnitude is smaller and horizontal de- formation is relatively weak; （2） the maximum principal strain of this earthquake zone in 1999--2007 is transition zone from positive to negative strain, the minimum principal strain in 2009--2011 also is transition zone from positive to negative strain, which is rela- tively large in 1999--2007; （3） the maximum shear strain of this earthquake zone is rela- tively small, and also is transformation zone for the left and right rotary; （4） the result of the continuous station shows that the earthquake happened in a almost pure thrust tectonic regime, the coseismic deformation is small, its scope is in the range of 10 kilometers from the epicenter; （5） there are no anormaly found in short-time GNSS observations before the earthquake, but there is anabnormaldeformation deficit in trend.
出处
《地震》
CSCD
北大核心
2014年第2期115-123,共9页
Earthquake
基金
地震行业科研专项(201208006
301308009)
科技支撑项目(2012BAK19B01-2)资助
关键词
区域水平形变
青藏高原东北缘
形变异常
岷县漳县MS6
6地震
The northeastern edge of Qinghai--Tibetan plateau
horizontal deformation
Deformation anomaly
Minxian--Zhangxian earthquake
