GPS时间序列揭示地震前兆的初步探索

PRELIMINARY DISCUSSION ON GPS TIME SERIES MANIFESTING EARTHQUAKE PRECURSOR

地震的很大一部分能量在震前会以各种形式缓慢释放,从而形成各种前兆,不同的孕震阶段有不同的前兆表现.通过用离散小波变换等方法对国内和国外两次大震周围的GPS站位移时间序列进行分析,结果发现:两次地震前都出现了站点运动态势的改变,时间大约从地震前1～2年或稍长时间开始,地震后又恢复了常态.GPS揭示的这种出现在低频、长周期信息中的异常有可能是地震中、长期前兆.

Much energy of an earthquake may release slowly in various forms before earthquake burst, and thus forms different earthquake precursors. It shows that there are different precursors in different stages of earthquake generation. Analyzing and processing displacement time series of GPS stations around domestic and overseas two strong earthquakes by wavelet transformation, we found that movement situations changed. In 1-2 year or longer before earthquake anomaly appeared and after earthquake it became normal. This anomaly which appears in the formation of low frequency and long-period may be middle-long earthquake precursor.