台灣東部板塊縫合帶之地表變形與大地構造研究：雷達干涉、宇宙射線暴露定年及斷層力學分析(II) 位於台灣東部的台東縱谷，分隔了中央山脈與海岸山脈，一直被視為台灣島上最重要的構造線，標示著菲律賓海板塊與歐亞大陸板塊的縫合帶。此處的地表變形速率相當快速，每年吸收了3 公分的縮短量。本研究預計針對台灣東部板塊縫合帶，以衛星雷達影像所衍生的測量方法，偵測區域的微量地表變形行為。由於雷達差分干涉法一般只能在平原地區施測，在山區或植被較厚的地區則受到許多限制，本研究因此將應用新開發的永久散設體干涉測量法，觀測研究區內的地表變形。永久散射體干涉測量法尋找地面固定散設點，針對多張影像進行運算，克服本研究區多山的地形，有效獲得地表變形資訊。此外，今年度亦將從事短基線長差分干涉技術，檢驗永久散射體差分干涉的結果，提升時間與空間上的解析度，進一步界定活動斷層位置。為了更進一步了解台灣東部縱谷側中央山脈的抬升過程及構造演化，需要了解不同時間尺度的構造活動情況。本研究因此於今年度增加宇宙射線暴露定年法，研究長期暴露在地表的河流階地以及流域盆地的堆積物，以定量更新世以來的造山運動速率。本研究亦將配合詳細的野外地質調查，並藉由分析岩石之脆性變形，了解區域之應變與應力來源，進一步與雷達干涉成果比對，探討當地之地表變形歷史與構造活動情形。 Surface deformation and tectonics of the eastern Taiwan suture zone: Radar interferometry, cosmic ray exposure dating and fault mechanism study On the eastern side of the Taiwan mountain belt, the Longitudinal Valley between the Central Range and the Coastal Range, marks the suture zone between the Eurasian plate and the Philippine Sea plate. Across this valley, a present-day relative velocity of about 3 cm/yr has been detected by geodetic means. This project aims at applying the space-borne radar technique to determine the surface deformation of the eastern Taiwan suture zone in detail. As Taiwan situated in a subtropical area, it is considered that both the steepness of mountains and the dense vegetation on land would provide the essential difficulty for the application of C-band SAR. In this study, we thus tend to apply the persistent scatterers (PS) interferometry to deal with this difficulty. The PS technique is an advanced tool for processing series of interferometric SAR data aiming at millimetric precision in ground deformation mapping. In the coming year, we will apply another technique, the small baseline (SB) interferometry, to examine the result of the PSInSAR and improve its spatial and temporal resolution. This examination will largely help us to define the locations of active faults and their activities. In order to better understand the uplift process and tectonic evolution of the eastern flank of the Central Range at different time scales, we tend to add a new dating technique in this research: the Cosmic Ray Exposure Dating. This analysis will reveal the uplift rate and denudation rate of the river terraces and drainage basins in this area. Besides, for realizing the regional strain and the stress orientation, we will carry out a detail field investigation and a series of morphological and fault mechanism analysis. These results can be combined with the interferometric observation to obtain a better understanding of the neotectonics and the deformation history of the eastern Taiwan suture zone. 研究期間：9908 ~ 10007
