Seismo-Electromagnetic Study based on multiple ULF-EM stations in South East Asia

为了利用电磁现象减轻大地震的地质灾害，我们在人为噪声较少的印度尼西亚和台湾安装了一些超低频地磁传感器和甚低频接收器。为了研究岩石层-大气-电离层的耦合关系，本项目不仅分析了ULF和VLF，还分析了GPS-TEC数据。本项目最重要的发现是地震前3-10天地磁赤道地区的GPS-TEC显著下降，统计上M&GT；6(印尼、台湾和中国地区)和电离层异常的空间范围很大，超过1000公里。

In order to mitigate geohazard of large earthquakes with using electromagnetic phenomena, we have installed some ULF geoelecromagnetic sensors and VLF receivers in Indonesia and Taiwan, where there are less artificial noises. Not only ULF and VLF, but also GPS-TEC data have been analyzed in this project to study the lithosphere-atmosphere-ionosphere coupling. The most important finding in this project is significant decrease of GPS-TEC around geomagnetic equator 3-10 days before the earthquake with M>6 (Indonesia, Taiwan, and China regions) in statistics and a vast spatial extent of ionospheric anomaly, which is greater than 1000km.