Study of seismo-electromagnetic phenomena (lithosphere-atmosphere-ionosphere coupling)

主要结果可以总结如下。(1)日本观测资料的收集和分析广泛研究了两个重要的物理参数：(1)极低频辐射和(2)与地震有关的电离层扰动。对2004年新潟地震进行了事件研究，我们通过在名古屋的测向确定了ULF发射的明显前兆效应，我们可以在JJY-Kochi路径上探测到明显的电离层前兆扰动。另一个大地震，印度尼西亚苏门答腊岛地震被研究；我们可以确定这次地震的超低辐射和电离层扰动。此外，对电离层扰动与地震之间的关系进行了进一步的统计研究，取得了很好的成功。(2)意大利、希腊和台湾的VLF观测和数据分析这三个国家的VLF观测进展顺利，我们一直在继续进行数据分析。(3)岩石圈-大气-电离层耦合研究从VLF振幅波动的频谱分析可以看出，大气重力波是这种耦合最可能的候选者。我们已经将大量的地面数据与法国DEMETER卫星数据进行了协调，以进一步研究岩石圈-大气-电离层耦合机制。

The main results can be summarized as follows.(1)Data collection and analysis of observational data in JapanTwo important physical parameters are studied extensively : (1)ULF emissions and (2)ionospheric perturbations associated with earthquakes. Event studies have been performed for the 2004 Niigata earthquake, for which we have observed clear precursory effect of ULF emissions as determined by direction finding at Nagoya and we could detect clear precursory ionospheric perturbations on the JJY-Kochi path. Another large earthquake, Indonesia Sumatra earthquake was studied ; we could identify both ULF emissions and ionospheric perturbations for this earthquake. Further, a statistical study further on the correlation between ionospheric perturbations and earthquakes has been undertaken with a good success.(2)VLF observation in Italy, Greece and Taiwan and the data analysisThe VLF observations in these three countries are going good, and we have been continuing the data analysis.(3)Study of lithosphere-atmosphere-ionosphere couplingWe have suggested the atmospheric gravity waves as the most likely candidate for this coupling, as evidenced from the spectral analysis of VLF amplitude fluctuation. Our extensive ground-based data have been coordinated with the French DEMETER satellite data to study further the mechanism of lithosphere-atmosphere-ionosphere coupling.