由於活動斷層之斷層岩石(包含破裂帶與斷層核芯)在地震循環週期中，同時受到瞬間的地震破裂運動與長時間的地質機械作用的影響，使得斷層岩石的解析與判讀非常困難，也因此地震循環週期中斷層變形與其相關機制的知識仍舊匱乏。為了達到這個目的，結合地質觀察與模擬變形條件之岩石力學工作是必要的，例如，模擬從緩速到快速的斷層行為於破裂帶與斷層核芯材料。藉由目前台灣車籠埔深鑽計畫所獲得之活動斷層帶(斷層核芯)同震構造的瞭解，以及保存良好之斷層岩芯材料，我們針對相關的各子題建立地震循環週期中斷層核心與破裂帶的變形對比: (1)瞭解斷層核芯物質從同震到震間的摩擦行為，(2)檢視破裂帶物質在震間的變形行為，以及(3)測量破裂帶物質在同震的彈性變形。其中，子題(2)與(3)的概念已獲美國NSF贊助支持三年。我們相信這個結合自然與實驗室觀察的嘗試可以(1)重建地震循環週期中斷層變形的全圖譜，(2)提供地震活動斷層新的地震物理觀點，以及(3)延伸我們對斷層變形的瞭解以及對地震災害可能的重大應用。 ;Knowledge about fault deformation and its associated mechanism during the seismic cycle remains incomplete, due to the difficulty in deciphering the fault-zone rocks within fault core and damage zone, the consequence of both transient fault movement and long-term geomechanical response preserved in a fault. To this end, it is necessary to integrate geological evidence and laboratory work by which rocks were deformed, e.g., from slow to fast motion and from the slip plane to the surrounding host rock. By exploiting the current results of the Taiwan Chelungpu fault Drilling Project (TCDP) including well-documented seismically deformed materials within fault core and well-preserved borehole fault-zone cores, we focus on the topic of the contrast in deformation styles between the fault core and the damage zone throughout the seismic cycle through a group of interrelated sub-projects: (1) investigation of the transition in frictional properties of the fault-core material from coseismic to interseismic slip velocities, (2) examination of the bulk deformational behavior of damage-zone materials deformed at interseismic boundary conditions, and (3) measurement of the elastic stiffness of the damage-zone materials relevant to coseismic conditions. In particular, the sub-projects [2] and [3] derived from our concept was funded by NSF (1727661) for three years (Bulk rheology of fault damage zone materials and its implication for interseismic fault mechanics; Aug 1, 2017 to July 31, 2020). This field- and laboratory-based approach will likely (1) reconstruct a full spectrum of fault behavior during the seismic cycle, (2) reveal a new view of earthquake physics for a seismically active fault, and (3) expand our understanding of fault deformation together with significant applications to natural faults.
