[M-IS13] Atmospheric electricity: Application of technology for reducing disaster risks

[MIS13-P07] Relationship between pre-earthquake-related D-region electron density enhancement and lightning activity

*Masashi Kamogawa¹ (1.Global Center for Asian and Regional Research, University of Shizuoka)

Keywords:Earthquake, Precursor, Lightning

Data from the DEMETER satellite, operated from 2004-2010, reported a nighttime VLF field intensity reduction event preceding an earthquake of M>4.8, with a epicentre distance within 500 km and 4 hours before the earthquake (Nemec et al, GRL, 2008). To understand the origin of this decrease, an independent analysis was performed. The results indicate that this decrease in intensity is an extremely rare decrease, with an occurrence frequency of 4σ level, using an artificial seismic catalogue. A similar intensity decrease is also observed in active lightning activity just below the satellite, but a study of lightning activity when this leading phenomenon is observed using the WWLLN lightning catalogue from the University of Washington showed no particularly active lightning activity. Therefore, it was shown that this phenomenon of intensity decrease may have a strong relationship with the seismic preparation process.