地震為人類的居住帶來舉足輕重之影響，選擇居住環境時，眾所皆知應避開斷層帶。若能找到地震發生的時間與距離之規律，使其成為另一種居住的參考依據，將是一大福祉。 地震圓弧交叉的概念發想自李顯智教授，利用地震規模4.6以上之地震目錄，繪製地震事件排列之圓弧，兩條圓弧交叉的地方附近因為「應力集中交互作用」往後常會發生規模6以上的大地震。另外，在每一個大地震附近也經常發現在地震前一段時間內有地震圓弧交叉形成。 本研究沿用此觀念，探討非台灣地區的地震圓弧交叉。日本與阿拉斯加的地震和台灣一樣，主要由逆向斷層所引起，而加州與非洲的地震成因主要分別屬於剪切斷層與正向斷層。 從地震規模6以上的大地震發生時間往前推5年，搜尋規模4.6以上的地震事件並繪製圓弧交叉，記錄時間與距離，並且分析地震的裂縫長度與規模的分布情形。然後，重新繪製與分析規模6以上的大地震往前推7年之規模4.8以上之地震圓弧交叉，進行穩定性分析。 ;Earthquakes have a significant impact on human dwellings. Everyone knows that we should avoid fault zones when finding a place to settle down. It will be a great fortune if we can find the regulation of the occurrence time and the locations of strong earthquakes and let it be another residential parameter. The concept of the intersection of circular arcs of earthquakes was proposed by Professor Lei, Hin-Chi. Using the earthquake events with magnitudes over 4.6 to plot an intersection of arcs of earthquakes, one can usually find a strong earthquake (called Main Shock) with magnitude over 6 near the intersection due to the interaction of two systems of stress concentrations. On the other hand, near to every strong earthquake usually there was an intersection of arcs of earthquakes formed before it. This thesis follows the above concept to study the intersections of arcs of earthquakes in areas other than Taiwan. Earthquakes in Japan and in Alaska are more similar to those in Taiwan. They are mainly caused by reverse fault. And earthquakes in California and in Africa are respectively mainly caused by strike-slip fault and normal fault. We try to construct the intersection of arcs of earthquakes with events over 4.6 formed in a period of five years before each selected strong earthquake over 6. The distance between each strong earthquake and the intersection point of the arcs of earthquakes are recorded. The time interval between the occurrence of each strong earthquake and the confirming time of the intersection of arcs of earthquakes is also measured. The lengths of the faults corresponding to the main events along the arcs of earthquakes are analyzed. To test the stability of our method, we also repeat our analysis for the events over 4.8 in a period of seven years before each strong earthquake.
