宫城Mw9.0级地震前日本IGS站GPS时间序列分析

为探讨日本宫城Mw9.0级地震前IGS(国际全球导航卫星服务)站的运动特征,针对日本7个IGS站4年(2007—2011)的观测资料,分别采用多项式拟合、小波降噪的方法分析站点水平方向运动的变化,采用小波分析、三角函数建模的方法分析竖向运动的变化.研究结果表明:宫城地震前6个月,日本境内多个IGS站竖向隆起速率加快,北方向运动速率减慢,东方向存在较陡的跳动现象. 

Time Series Analysis of Japan IGS Sites before Tohoku Mw9.0 Earthquake

To investigate the movement characteristics of IGS (International GNSS (global navigation satellite system) Service) sites in Japan before Tohoku Mw9.0 earthquake, the observed data obtained by 7 IGS sites located in Japan from January, 2007 to March, 2011 were utilized. A polynomial fitting method and a wavelet denoising method were employed to analyze the horizontal movement, and the vertical movement was assessed by the wavelet analysis method and the trigonometric function modeling. The result shows that before the Tohoku Mw9.0 earthquake, the up component of ground movement at most of the IGS sites in Japan turns to be fast, the north component becomes slow, while the east component changes irregularly.