搜索结果: 1-12 共查到“地球物理学 ULF”相关记录12条 . 查询时间(0.078 秒)
云南景谷MS6.6地震前地磁ULF异常信号变化
地震 ULF异常信号 景谷
2019/1/4
采用云南地磁台站通海、景谷、勐腊磁通门记录秒采样数据，分析了3个台站当地时间22时到次日2时（世界时15-19时）之间垂直分量（Z）和水平分量（H）在特定0.01~0.05 Hz范围的辐射谱强度。结果表明，在震前垂直分量并没有强烈和清晰的ULF信号强度，3个台站水平分量ULF信号趋势性上升和震时反常的信号衰减现象，则反映震前超低频地磁信号产生扰动。
Preseismic ULF effectand possible interpretation
Ultra-Low Frequency emission seismicity Alfven waves
2015/9/14
We present the results of ULF magnetic field observation at Karimshino station (Kamchatka, Russia). Using a case study we discovered an effect of suppression of ULF intensity about 2-6 days before rat...
A possible model for initiationof ULF oscillation in magma
ULF oscillations magma volcano electromagnetic emission
2015/9/14
During the period just prior to an earthquake, an electomagnetic emission develops over seismic zones. In this paper, a model of excitation of magnetic fields over zones of volcanic activity is propos...
Depression of the ULF geomagnetic pulsation related to ionospheric irregularities
ULF ionosphere Alfven seismicity
2015/9/14
We consider a depression in intensity of ULF magnetic pulsations, which is observed on the ground surface due to appearance of the irregularities in the ionosphere. It is supposed that oblique Alfven ...
The study of local sources of ULF geoelectric signals with steep fronts
geoelectricity earthquakes prediction method VAN
2015/9/14
The method for recognition and monitoring of ULF electrotelluric signals with steep fronts is presented. The method is based on the multicomponent measurements of the geoelectric field and recognition...
2004年8月3日近地TC-1卫星在磁尾XGSM~－12RE的等离子体片内,观测到了伴随着高速流的低于离子回旋频率的波,即超低频波(ULF,Ultra Low Frequency).该波垂直分量的振幅在高速流及其振荡减速期间大致相当;而平行分量振幅在高速流时明显大于其振荡减速时. 利用一个扰动双流模型对完全磁化离子横场漂移驱动的电磁不稳定性计算后,预测结果表明:(1)对于垂直分量来说,横场漂移速度...
汶川MS8.0级地震前后ULF电磁辐射频谱特征研究
汶川地震 电磁辐射 ULF频段 快速傅里叶变换(FFT) 小波变换
2013/11/4
本文基于电磁波频谱理论研究方法,对2008年四川汶川MS8.0地震前后金河、剑阁及郑州二砂三个电磁波台站的观测资料进行FFT和小波变换分析,研究了电磁辐射数据快速傅里叶频谱变化特征和在不同尺度下小波变化的分解,发现在汶川地震前确实有异常信息存在.结果表明:(1) FFT动态谱图像说明,地震前电磁波频谱变化特征较明显,在时间、频段上均显示了阶段性进程特征,且随着震中距的增大,辐射能量越小,异常出现的...
Application of polarization ellipse technique for analysis of ULF magnetic fields from two distant stations in Koyna-Warna seismoactive region, West India
Application polarization ellipse technique analysis ULF
2010/10/21
A new approach is developed to find the source azimuth of the ultra low frequency (ULF) electromagnetic (EM) signals believed to be emanating from well defined seismic zone. The method is test applied...
Multifractal analysis for the ULF geomagnetic data during the 1993 Guam earthquake
Multifractal analysis ULF geomagnetic data Guam earthquake
2009/11/9
In our previous papers we have shown that the fractal (monofractal) dimension (Do) showed a significant increase before the Guam earthquake occurred on 8 August, 1993. In order to have a further suppo...
Fractal analysis for the ULF data during the 1993 Guam earthquake to study prefracture criticality
Fractal analysis ULF data Guam earthquake prefracture criticality
2009/11/9
An extremely large earthquake (with magnitude of 8.2) happened on 8 August 1993 near the Guam island, and ultra-low-frequency (ULF) (frequency less than 1 Hz) electromagnetic fields were measured by 3...
An attempt to find precursors in the ULF geomagnetic data by means of flicker noise spectroscopy
ULF geomagnetic data means of flicker noise spectroscopy
2009/11/9
The flicker noise spectroscopy which is a new phenomenological method for the retrieval of information contained in chaotic time signals, is based on the analysis of recognizable irregularities (pulse...