HR: 0830h
AN: T51E-0207    [PDF]
TI: Seismo-Ionospheric Precursors
AU: * Liu, J
EM: jyliu@jupiter.ss.ncu.edu.tw
AF: Institute of Space Science, National Central University, Institute of Space Science, National Central University, Chung-Li, 320 Taiwan
AU: Chen, Y
EM: ychen@stat.ncu.edu.tw
AF: Institute of Statistics, National Central University, Institute of Statistics, National Central University, Chung-Li, 320 Taiwan
AU: Chuo, Y
EM: yjchuoGjupiter.ss.ncu.edu.tw
AF: Institute of Space Science, National Central University, Institute of Space Science, National Central University, Chung-Li, 320 Taiwan
AB: Large earthquakes are often preceded or accompanied by signals of a different nature: electric, electromagnetic, or luminous, although seismic waves are the most obvious manifestation. Recently, seismo-ionospheric phenomena have received considerable discussions. To investigate possible seismo-ionospheric precursors, we statistically examine the relationship between electron density variations at the ionospheric F2 peak observed by a local ionosonde and 184 earthquakes with magnitude 5.0 or larger, which occurred in 170 days during 1994~1999 in the Taiwan area. Results demonstrate that the electron density abnormally decreases during the afternoon period, 1200~1800 LT, within 5 days before the earthquakes. The odds of the earthquakes with the precursor increasing in the earthquake magnitude but decreasing in the range between the epicenter and the ionosonde confirm the existence of an imminent seismo-ionospheric precursor.
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2435 Ionospheric disturbances
DE: 7223 Seismic hazard assessment and prediction
DE: 8159 Rheology--crust and lithosphere
SC: Tectonophysics [T]
MN: 2003 Fall Meeting