本論文利用中壢電離層探測儀所記錄每15分鐘之電離層F2層層峰電子濃度NmF2，研究1994-1999年間188個ML≧5.0於170天內發生的地震期間之變化。結果發現地震前五天至後三天1000-2000LT，NmF2有明顯的異常減少。依此特性，計算每日1000-2000LT觀測值與對應中位數差建立不同參考區間並篩選六年內的異常天。利用勝算分析地震規模與異常天出現機會，探討兩物理量間的關係，得知異常天的出現機會與地震規模呈一正比關係。綜合以上結果，顯示電離層異常似乎與地震能量有關。 In this thesis, the maxima plasma density, NmF2, is employed to study the anomalies of the ionospheric electron density appearing during occurrences of ML≧5.0 earthquakes in 1994-1999. It is found that the NmF2 anomalous decrease at 1000-2000LT from 5 days before to 3 days after the earthquakes. Based on the observed characteristic, the anomaly days during the 6 six years are identified. Finally, an odd study is applied on the identified anomalies. The result shows that the odd is proportional to the magnitude of the earthquake. This suggests the anomaly is earthquake energy related.
