东北地区GPS连续观测站的变化

THE CHANGE OF CONTINUOUSLY MONITORING GPS SITES OF NORTHEAST CHINA

根据东北地区GPS连续观测站数据计算位移变化量,将结果分离为线性趋势变化部分和非线性变化部分。据此分析了东北地区的地壳运动,异常特征及其与中强地震孕育发生的关系。结果显示,相对全球框架基准,东北地壳以27.06mm/a的速度向南东方向位移;GPS站点的非线性变化在地震前几个月至2年出现不同程度的异常变化,震级相对较大时,异常范围大,出现异常变化的站点也多;单个站点出现异常时,常常是站点附近地区有中小地震发生。无中、强地震孕育发生的时期,站点位移变化也相对稳定,一般无明显异常变化。

We calculated the data from continuously monitoring GPS sites in Northeast China,then divided the results into two parts, linear trend change and nonlinear variation, and analyzed the crustal movement, anomaly and the relationships among the crustal movement, anomaly and the preparation and occurrence of medium strong earthquake in Northeast China.The results showed that the crust in Northeast China moved toward southeast at the speed of 27.06mm/a;the anomaly in varying degree from continuously monitoring GPS sites appeared about 2 months - 2 years before the earthquake happened; when the magnitude was large,the range of the anomaly was large, many GPS sites which had anomaly were as well ;when the anomaly happened in singular site, it may showed that there was moderate and small earthquake around the site;if there was no the preparation and occurrence of middle,large earthquake, the change in displacement of the sites were relatively stable and usually didn＇t have obvious change.