九二一大地震後，經檢視全省磁力連續觀測資料發現，位於車籠埔斷層兩端的磁力站—鯉魚潭站及灣丘站，都觀測到磁力異常訊號，這些異常訊號與地震的發生有時間上的巧合。一般認為，當岩層受到應力作用而產生裂隙，地層內所含的帶磁礦物會散發在空間中，造成地磁場的變化。本計畫除了協助更新三分量地磁連續觀測網的觀測儀器外，同時也分析新建置的全省三分量地磁連續觀測網資料，以了解地磁場強度改變與地震活動的關聯性。 本計畫預計發展預報品質的評估方式以及進行資訊分析工具的初步研究；後續擬開發資訊分析工具並將其應用於同時聯合地電與地磁觀測的TIP機率預報中。藉由資訊理論的應用以及基於地電、磁觀測資料之TIP預報方法的整合，我們將得以更全面的方式探討地震前兆現象，並期待能更進一步提升整體預報表現。 本研究計畫將利用上述分析之長期間(1994年-2021年)電離層異常資料，研究地震前電離層異常的特性。除了時間上的異常之外，本研究同時分析電離層異常區域與震央之間的關係，建立地震前電離層異常的時空分布圖。當觀測到電離層異常時，可作為地震預警判斷之用。 ;After 921Chi-Chi earthquake, numerous magnetic anomaly signals were observed in the northern and southern parts of the Chelungpu fault, and it is coincided with the time of Chi-Chi earthquake occurred. It is generally believed that the magnetic minerals contained in the formation will be dispersed in space, causing changes in the geomagnetic field. This project analyzes the new 3-components geomagnetic observation network to understand the associated with seismicity and changed in tectonic stress. we plan to investigate methods for assessing probability forecast and develop tools for informational analysis. we plan to develop the tools of informational analysis and apply them in the integrated TIP forecasting system. With the application of informational theory and the integration of the previously developed TIP forecasting systems, we can have a better comprehension about the pre-seismic electromagnetic phenomena. By employing the above-mentioned long-term ionospheric anomaly results during 1994-2021, the purpose of this project is to study the characteristics of ionospheric anomaly, such as the temporal precursor and the relationship between the spatial anomaly and the earthquake. The ionospheric time-space anomalous distribution map will be further developed for the seismic precursor in the ionosphere.
