Probing the lower ionospheric perturbations associated with earthquakes by means of subionospheric VLF/LF propagation  

作　　者：Masashi Hayakawa 

机构地区：[1]Advanced Wireless Communications Research Center and Research Station on Seismo Electromagnetics,The University of Electro-Communications,1-5-1 Chofugaoka,Chofu Tokyo 182-8585,Japan [2]Earthquake Analysis Laboratory,Information Systems Inc.,Kita-Aoyama 2-12-42-R305,Minato-ku,Tokyo 107-0061,Japan

出　　处：《Earthquake Science》2011年第6期609-637,共29页地震学报（英文版）

摘　　要：There have been reports for many years that the ionosphere is very sensitive to seismic effects, and the detection of ionospheric perturbations associated with earthquakes （EQs） attracts a lot of attention as a very promising candidate for short-term EQ prediction. In this review we present a possible use of VLF/LF （very low frequency （3-30 kHz）/low frequency （30-300 kHz）） radio sounding of seismo-ionospheric perturbations. In order to avoid the overlapping with my own previous reviews, we first show some pioneering results for the Kobe EQ and we try to present the latest results including the statistical evidence on the correlation between the VLF/LF propagation anomalies （ionospheric perturbations） and EQs （especially with large magnitude and with shallow depth）, medium-distance （6-8 Mm） propagation anomalies, the fluctuation spectra of subionospheric VLF/LF data （the effect of atmospheric gravity waves, the effect of Earth＇s tides, etc.）, and the mechanism of lithosphere-atmosphere-ionosphere coupling. Finally, we indicate the present situation of this kind of VLF/LF activities going on in different parts of the globe and we suggest the importance of international collaboration in this seismo-electromagnetic study.There have been reports for many years that the ionosphere is very sensitive to seismic effects, and the detection of ionospheric perturbations associated with earthquakes （EQs） attracts a lot of attention as a very promising candidate for short-term EQ prediction. In this review we present a possible use of VLF/LF （very low frequency （3-30 kHz）/low frequency （30-300 kHz）） radio sounding of seismo-ionospheric perturbations. In order to avoid the overlapping with my own previous reviews, we first show some pioneering results for the Kobe EQ and we try to present the latest results including the statistical evidence on the correlation between the VLF/LF propagation anomalies （ionospheric perturbations） and EQs （especially with large magnitude and with shallow depth）, medium-distance （6-8 Mm） propagation anomalies, the fluctuation spectra of subionospheric VLF/LF data （the effect of atmospheric gravity waves, the effect of Earth＇s tides, etc.）, and the mechanism of lithosphere-atmosphere-ionosphere coupling. Finally, we indicate the present situation of this kind of VLF/LF activities going on in different parts of the globe and we suggest the importance of international collaboration in this seismo-electromagnetic study.

关 键 词：Earth-ionosphere waveguide subionospheric VLF/LF propagation seismo-ionosphericperturbation earthquake lithosphere-atmosphere-ionosphere coupling 

分 类 号：P352.3[天文地球—空间物理学] P315.72[天文地球—地球物理学]