2004-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/690473摘要：台灣位於歐亞大陸板塊與菲律賓海板塊之接合處，此兩板塊每年以8.2 公分的顯著 速度相互靠近，導致台灣島上發生劇烈的變形縮短作用。由於板塊聚合的速度非常快， 台灣島的地震活動頻繁，在歷史的記錄上，地動與地裂帶來的自然災害，對島上人民 之生命與財產造成嚴重的威脅。過去一百年來，多次的歷史地震皆在地表形成地震斷 層；其中嘉南地區近百年來已有十五次以上規模大於6 的地震發生。根據中央地質調 查所的資料，台灣目前的活動斷層多達42 條，其中有一大部份位於人口與建築物密集 的西部麓山平原區，活動斷層對台灣大眾潛在的危險與威脅可想而知。因此有必要進 一步瞭解特定斷層活動的特性，例如其幾何形貌、滑移速率、潛移或鎖定、再現週期、 斷層分段、發生地震的規模等，以提供未來國土規劃與減低地震災害的參考。 對斷層位置之辨識及其活動性之監測，在九二一集集大地震之後，更加突顯其重要 性。在對斷層活動性之評估方式當中，大地測量之方法為可在較短時間內獲得相對較 高精度之有效手段之一。有鑑於此，本計畫預計於四年內，完成臺灣西南部活動斷層 之近斷層GPS 與精密水準測量監測網之建立，分別針對新化斷層<br> Abstract: The Taiwan orogeny results from the collision between the Luzon volcanic arc of the Philippine Sea plate and the Chinese continental margin of the Eurasian plate. According to the recent GPS measurements, the present-day convergence rate of the Luzon arc with respect to the Chinese continental margin is about 81.5 mm/yr in the azimuth 306°. As an active collision zone between the Luzon arc and the China continental margin, the Taiwan mountain belt, particularly its south-central part, is undergoing strong crustal shortening and rapid uplift. From the point of view of historical earthquake, the southwestern Taiwan occurred several destructive earthquakes with significant surface ruptures during the last century. Based on the data of Central Geological Survey, there are 42 active faults in Taiwan area. Most of them locate in the western Foothills and coastal plain where the population is very dense. Thus, the detailed study of seismic hazard and active fault is a crucial point of the hazard assessment and mitigation. As a consequence, it is extremely important to characterize the location and the subsurface geometry of active faults, the recurrence time of destructive earthquakes, slip rate and segmentation of active faults and fault parameter such the locking depth. After destructive Chi-Chi earthquake, the monitoring of potential earthquake fault is the mainstream of earthquake geology in Taiwan. From the seismic hazard of view, the monitor of deformation built up during the interseismic period is a major concern for seismic hazard assessments in Taiwan. The precise geodetic method is one of the powerful tools to obtain the crustal deformation during the short period. We aim at establish the geodetic network in southwestern Taiwan across the major active faults such as the Chiuchiuhgkeng Fault, The Tachienshan Fault, Chukou Fault, Houchiali Fault, the Chishan Fault, Liukuei Fault, And Fongshan Fault. The goals of this study focus on monitoring crustal deformation in southwestern Taiwan by using Continuous GPS and survey mode GPS, together with the precise leveling. We try to combine the geodetic data with microseismic array and geologic observation in order to build up the mechanical model for the observed deformation. Finally the numerical simulations will be carried out to obtain the possible mechanical explanations and the significance of the active deformations. This year we will focus on the fault activity of Hsinhua fault and Houchiali fault using 20-30 semi-permanent GPS stations with 7 permanent stations in this area. We will combine this results with PSInSAR techniques for the monitoring crustal deformation.活斷層GPS 連續追&#36394站永久散射合成孔徑雷達干涉半連續GPS 追&#36394站active faultcontinuous GPS stationsPSInSARsemi-permanent stations