| Summary: | 博士 === 國立中央大學 === 太空科學研究所 === 101 === It has been found that the crust deformation before large earthquakes could activate electromagnetic environment charges, which generate the atmospheric field, result in atmospheric luminosity or lightning phenomena, and further disturb the ionospheric electron density and temperature before large earthquakes. In this dissertation, temporal and spatial variations of lightning during 307 M>5.0 earthquakes in Taiwan in 1993-2004 are examined. Results show that the lightning occurrence before land earthquakes are greater than that of after. However, there are no significant differences before and after sea earthquakes. These suggest that the lightning activities during the earthquake might be related to the conductivities of the ground. Moreover, the ionospheric electron density, electron temperature, O+ ion density, ion temperature and whistler counts observed by DEMETER satellite during the 2010 M8.8 Chile earthquake are investigated. Results show the electron, ion densities and ion temperature increase, while the whistler count decreases 9－19 days before the earthquake. It is found that the GPS TEC also increases during the same period. The cross-comparisons of the temporal and spatial results confirm that electron and ion densities are sensitive detecting anomalous related to the earthquake. The atmospheric and ionospheric anomalies appearing before imply that the lithosphere-atmosphere-ionosphere coupling is important.
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