摘要
对法国DEMETER卫星记录的2008年5月12日汶川MS8.0地震前10天连续轨道的电磁数据进行了时-频功率谱分析,发现在震前第6天存在低于截止频率的窄带电磁辐射.为进一步分析该电磁辐射的传播特性,采用奇异值分解方法在时-频域下分析了电磁辐射的极化特性、波矢量特性等电磁波传播特性,发现该电磁辐射呈现出很强的平面波特征,传播方向呈现上行传播.而在震前10天连续轨道数据的分析中,在非震区上空并未发现类似的异常现象.
Based on the electromagnetic data recorded by DEMETER satellite during the past ten days before 12 May 2008 Wenchuan Ms8.0 earthquake, an anomaly be- low cut-off frequency is detected at the sixth day before the earthquake using power spectrum analysis. In order to learn the propogation characteristic of the abnormal e- lectromagnetic emmision, singular value decomposition （SVD） method is used to get polarization and wave vector of the emmison signals. The result shows that the anom- aly reveals plane wave features and it propagated upwards. No similar phenomena are found above other non-seismic regions.
出处
《地震学报》
CSCD
北大核心
2010年第6期641-648,共8页
Acta Seismologica Sinica
基金
国家科技支撑项目(2008BAC35B01)
哈尔滨工业大学(威海)研究基金项目(HITWH2B200805)资助
关键词
极化特性
电磁辐射
地震
polarization characteristic
electromagnetic emission
earthquake
