本研究是將目前在台灣地區所使用最強地震弧交叉的概念嘗試去應用在加州及阿拉斯加地區及它們附近的區域。從地震目錄中規模6.0以上之地震逐步往下降規模，直到第一個地震弧交叉出現即為該區域之「最強地震圓弧交叉」或「主地震圓弧交叉」。而若在同規模下同時出現多條相似的地震弧，將選取弧交叉形成確認時間最早的來做為最強地震弧交叉。再來，將會對該交叉進行分析和統計，並試著尋找往後發生之強烈地震與其關聯性。 同時，本研究會建立地震目錄來進行研究，地震目錄分為阿拉斯加地區和加州地區，所選取的資料兩者皆為地震目錄中2005年上半年至2014年下半年之地震事件。在這當中，阿拉斯加地區共發現了19個最強地震圓弧交叉，加州地區則發現了15個最強地震圓弧交叉。交叉形成後發生大震的圓形預測範圍，使用交叉點為中心70公里為半徑，或以Lmin/4為半徑，此處Lmin/4代表交叉兩弧中較短弧弧長的四分之一長度。其後，將各個交叉視為一個案例，探討該交叉在選取範圍內後續發生大震所需要的天數，爾後進行2005年上半年至2014年下半年間所有發現交叉的統計及分析，並探討對未來之大震之影響。 阿拉斯加地區及加州地區和台灣同屬環太平洋地震帶，阿拉斯加下方的阿留申群島是屬於火山帶和隱沒帶，而加州地區為聖安地列斯斷層橫跨南北的錯動性板塊，本研究將探討最強地震圓弧交叉應用於此兩地區的結果。 ;This study attempts to apply the concept of "the strongest intersection of the circular arcs of earthquakes" which currently used in Taiwan to regions in and around California and Alaska. When searching for the earthquake events from the earthquake catalogue, we gradually decrease the magnitude of earthquakes events from 6 or higher until the first intersection of the circular arcs appears and call it "the strongest intersection of the circular arcs of earthquakes". If in one region there are multiple circular arcs at the same time with the same minimum event magnitude, the arcs with the earliest confirming time will be selected to from the intersection. Then, the intersection will be analyzed and we try to find the relation between the intersection and the nearby strong earthquakes happened after the formation of it. At the same time, the study will establish an earthquake catalogue for research. The earthquake catalogue is divided into two regions of Alaska and California. And the selected data for earthquake events are from the first half of 2005 to the second half of 2014. In Alaska we found 19 strongest intersections of the circular arcs of earthquakes, and in California we found 15 strongest intersections of the circular arcs of earthquakes. The circular prediction reigon of strong earthquakes takes the intersection point as the center and 70 km or Lmin/4 as the radius. Here Lmin/4 represents a quarter of the shortest arc length in the two arcs of the intersection. Afterwards, each intersection is regarded as a case to explore how many days required for the subsequent strong earthquakes in the prediction area, and then we carry out the statistics and analysis of all the intersections from the first half of 2005 to the second half of 2014, and then discuss the impact of the strong earthquake. Alaska、California and Taiwan are all belong to the Circum-Pacific Seismic Zone. The Aleutian Islands which located below Alaska belong to volcanic zone and subduction zone, and San Andreas Fault is transform fault crossing California from north to south. The study will explore the application of the strongest intersection of the circular arcs of earthquakes in these two regions.
