Middle latitude LF (40 kHz) phase variations associated with earthquakes for quiet and disturbed geomagnetic conditions
Middle latitude LF (40 kHz) phase variations associated with earthquakes for quiet and disturbed geomagnetic conditions
复制标题
DOI：
10.1016/j.pce.2003.08.061
复制
发表时间：
2004-01-01
影响因子：
3.7
通讯作者：
Hayakawa, M
中科院分区：
文献类型：
--
作者：
Rozhnoi, A;Solovieva, MS;Hayakawa, M
本文利用OminiPAL数字接收机在日本-堪察加2300 km路径沿着两年的观测资料，研究了亚电离层低频信号（40 kHz）的相位（P）和振幅（A）异常。本文提出了无地震活动时地磁平静和扰动条件下背景P和A日变化的经验模型。我们特别注意大磁暴期间的P和A特征。定义了低频信号对地磁和地震形变影响的敏感阈值。两例低频信号在夜间出现的海湾状特征，是低频信号的明显地震前兆。通过统计研究发现，低频信号效应只在M ≥ 5.5的地震中出现，并讨论了这种效应的可能机制。(C)2004年由Elsevier Ltd.出版。
The phase (P) and amplitude (A) anomalies in subionospheric LF signal (40 kHz) along the path Japan-Kamchatka of 2300 km have been studied for the data observed by means of a digital OminiPAL receiver for 2 years. The empirical model of background P and A daily variations for quiet and disturbed geomagnetic conditions in the absence of seismic activity is developed. We pay special attention to the P and A features during large magnetic storms. A sensitivity threshold of LF signal to deforming influence of the geomagnetic and seismic factors is defined. Two cases of bay-like behavior of LF phase and amplitude in nighttime are described as a clear earthquake precursor of LF signal. We have found from the statistical study that LF signal effect is observed only for earthquakes with M greater than or equal to 5.5 and we discuss the possible mechanisms of the effect. (C) 2004 Published by Elsevier Ltd.