Collaborative Research: Patterns of Serial Fault Rupture in Taiwan

本计画研究台湾两个活动断层系统，车笼埔断层与纵谷断层，它们分别在1999年与1951年的大地震中破裂，以探讨断层的复发行为与破裂模式的时间变异性。车笼埔断层和纵谷断层破裂时间序列的获得，为断层序列破裂和断层相互作用的物理模型提供了约束条件。这些结果与地震危险性分析有关，通过考虑导致地震的物理过程，包括相邻断层破裂的相互作用，先前破裂对断层的影响，地质构造和断层几何形状对破裂终止和地震行为的影响。沿着沿着车笼埔断层的古地震研究描述了地震复发和位移历史。例如，如果类似1999年的地震复发频率要低得多，那么同一纬度的其他结构将不得不在应变消除中发挥重要作用。这些调查的结果有影响的理解的物理过程中的应变缓解个别故障和造山运动。端元假说，从无模式或随机复发到高度集群行为，正在使用沿着沿着车笼埔和邻近逆断层获得的地震时程进行测试。该项目还描述了纵向谷断层的活动断层。确定选定的少数沿海海洋阶地的海岸线角度的海拔限制了纵向山谷沿着的千年率。对沿着十姑峦河的河流阶地进行地质填图和测年，提供了纵向河谷和东部沿海地区之间的时间平均抬升速率。

Charles RubinEAR-0208444This project undertakes studies of two active fault systems in Taiwan, the Chelungpu and Longitudinal Valley faults, which ruptured during large earthquakes in 1999 and 1951, in order to address recurrence fault behavior and the temporal variability of rupture modes. Acquisition of rupture time series on the Chelungpu and Longitudinal Valley faults provide constraints on physical models of serial fault rupture and fault interactions. These results bear on seismic hazard analysis, by considering the physical processes that lead to an earthquake, including the interaction of adjacent fault ruptures, the effect of prior ruptures on a fault, the influence of geologic structure and fault geometry on rupture termination and aseismic versus seismic behavior.Paleoseismic studies along the Chelungpu fault are characterizing its earthquake recurrence and displacement history. For example, if the recurrence of 1999-like earthquakes is far less frequent, then other structures at the same latitude would have to play an important role in strain relief. Results from these investigations have implications for understanding the physical processes of strain relief on individual faults and of mountain building. End-member hypotheses, ranging from unpatterned or random recurrence to highly clustered behavior, are being tested using earthquake time histories obtained along the Chelungpu and adjacent reverse faults.The project also characterizes the active faults of the Longitudinal Valley faults. Determining the elevations of shoreline angles for a select handful of coastal marine terraces is constraining the millennial rates along the Longitudinal Valley. Geologic mapping and dating of the fluvial terraces along Shiouguluan River are providing the time-averaged uplift rates between the Longitudinal Valley and the eastern coastal region.