2011年日本9.0级地震前后GPS基线时间序列分析*

(中国地震局第一监测中心,天津 300180)

GPS基准站; 基线时间序列; 构造形变场; 日本9.0级地震

Analysis of GPS Baseline Time Series before and after Tohoku-oki M9.0 Earthquake in Japan in 2011
ZHANG Feng-shuang,ZHAN Wei,Sun Dong-ying

(First Crust Monitoring and Application Center,CEA,Tianjin 300180,China)

GPS reference station; baseline time-series; co-seismic deformation field; Japan M9.0 earthquake

备注

利用1999年初至2011年9月中国地壳运动观测网络基准站及中国大陆周边包含日本境内的IGS基准站的资料,分析了2011年3月11日日本9.0级地震前日本境内及周边IGS基准站基线时间序列的变化情况。讨论了该地震对中国大陆GPS基准站的同震影响,并对地震后中国大陆GPS基线时序结果的变化情况进行了总结分析。通过分析认为,日本大震后我国东部地区部分GPS基线开始转折拉伸,因而一定程度上缓解了这些基线的趋势性缩短,但是东部地区仍然有部分GPS基线的变化趋势基本不受日本地震的影响,近几年以来的趋势性异常至今仍然存在。

By the use of the data recorded by reference stations of the Project of “China Crust Movement Measuring Network” and IGS reference stations at the surrounding of the mainland of China including Japan from early 1999 to Sep.,2011,we analyze the variations of baseline time-series recorded by IGS reference stations before the Tohoku-oki M9.0 earthquake on Mar.11,2011 in Japan and its surrounding.Then we discuss about the co-seismic influence of Tohoku-oki M9.0 earthquake to the GPS reference stations in China,and summarize the changes of GPS baseline time series in China after the earthquake in Japan.By analyzing changes of GPS baseline time-series,we think that some GPS baseline time-series in the east of China turn to stretch after Tohoku-oki M9.0 earthquake,which can relieve its shortening tendency in some extent.However,there also exist some GPS baseline time-series whose tendency variations are almost not influenced by Tohoku-oki M9.0 earthquake,and its trend anomaly have kept for years in recent years.