【摘要】 主要研究了地震期间可能出现的物理现象对人工电磁信号传播产生的影响。这里采用的仿真方法是基于地形学网格划分的时域FDTD方法,主要关注的频率范围是50~250Hz(超低频)。为了精确地仿真地震期间可能出现的电磁环境,研究过程中主要考虑了震区地下动电效应电流源和电离层异常现象,同时也讨论天然电磁噪声(闪电)的影响。研究表明,在地震的特殊物理环境下,受到不同因素的影响,超低频电磁波的传播出现了不同类型的异常现象,这也证明了观测结果的正确性。最后,总结了地震期间的超低频电磁信号传播异常现象的规律,并指出了采用人工方式来监测和预测地震的可行性。更多还原

【Abstract】 This investigation focuses on the effect of abnormal physical mechanisms on the artificial electromagnetic (EM) signal propagation during earthquakes. The geodesic FDTD method is applied to this study to simulate EM wave propagation in extremely low frequency (ELF) range of 50-250 Hz. The effects of currents caused by electrokinetic effect and ionospheric anomalies are mainly considered, as well as the background noises (the lightning). The results show the propagation anomalies during earthquakes, which also prove the observation results by former researchers. Finally, basic phenomena of EM propagation anomalies are summarized and potentials of artificial monitoring earthquakes are proposed.更多还原