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

主要结果可归纳如下。（1）日本观测数据的数据收集和分析广泛研究了两个重要的物理参数：（1）ULF发射和（2）与地震有关的电离层扰动。对2004年的新泻地震进行了事件研究，我们观察到了名古屋定向所确定的ULF发射的明显的电离层扰动效应，并且我们可以检测到JJY-Kochi路径上的明显的电离层扰动。此外，对电离层扰动与地震之间的相互关系进行了进一步的统计研究，并取得了很大成功。（2）意大利、希腊和中国台湾地区的VLF观测及资料分析这三个国家的VLF观测工作进展顺利，我们一直在继续进行资料分析。（3）岩石层-大气层-电离层耦合的研究根据VLF振幅起伏的谱分析，我们认为大气重力波是这种耦合的最可能的候选者。我们广泛的地面数据与法国DEMETER卫星数据进行了协调，以进一步研究岩石圈-大气层-电离层耦合的机制。

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.