Electric and magnetic phenomena observed before the volcano-seismic activity in 2000 in the Izu Island Region, Japan
Electric and magnetic phenomena observed before the volcano-seismic activity in 2000 in the Izu Island Region, Japan
复制标题
DOI：
10.1073/pnas.072208499
复制
发表时间：
2002-05-28
影响因子：
11.1
通讯作者：
Tanaka, H
中科院分区：
文献类型：
--
作者：
Uyeda, S;Hayakawa, M;Tanaka, H
在日本伊津岛地区的主要火山地震活动之前，地电和地磁都观察到了超低频范围(约0.01赫兹)的显著异常变化。从火山地震活动开始前的几个月开始，新岛岛一些电极之间的地电势差与伊豆半岛阵列网络的地磁场变化的第三主分量之间的频谱强度开始增加，并在附近的6级地震之前达到顶峰。在两个相距较远的地点进行的两次不同测量中出现的类似变化似乎提供了支持震前电磁信号的事实的信息。
Significant anomalous changes in the ultra low frequency range (approximate to0.01 Hz) were observed in both geoelectric and geomagnetic fields before the major volcano-seismic activity in the Izu Island region, Japan. The spectral intensity of the geoelectric potential difference between some electrodes on Niijima Island and the third principal component of geomagnetic field variations at an array network in Izu Peninsula started to increase from a few months before the onset of the volcano-seismic activity, culminating immediately before nearby magnitude 6 class earthquakes. Appearance of similar changes in two different measurements conducted at two far apart sites seems to provide information supporting the reality of preseismic electromagnetic signals.