Collaborative Research: Paleoseismology and Paleogeodesy of the Sumatran Subduction Zone

本研究继续对苏门答腊俯冲带的古地震学和古地理学进行研究，以确定断层破裂之间的周期性、断层滑动模式的可重复性、地质构造对断层破裂的影响以及地震/地震耦合随时间的变化。这项研究的核心是使用珊瑚头（滨珊瑚和其他属），它们对海平面变化敏感，不确定性只有几厘米。年生长带给出的时间序列与几年的相对误差和U-Th测年的头部给出的日期与十年的误差。与地震有关的垂直形变的大小（古地震学）和地震间隔的形变（古地理学）正在从这些数据中确定。正在对结果进行建模，并使用历史地震（来自各种来源的地震图）来确定段边界是否影响历史断裂的尺寸。该项目的具体目标是：（1）更好地表征1681、1797和1833年地震的震源参数;（2）确定这些地震的南界;（3）将记录延伸到14世纪;（4）确定1861和1907年地震的震源特征;（5）模拟Summartan断层上大地震的历史地震图;（6）对1861、1797和1833年地震区的地震应变事件进行了分析。

EAR-0207690University of California-Santa CruzThis study continues investigations of the paleoseismology and paleogeodesy of the Sumatran subduction zone in order to determine possible regularity of periods between fault ruptures, repeatability of pattern of slip on faults, influence of geologic structure on fault rupture, and variation of seismic/aseismic coupling with time. The centerpiece of the study is the use of coral heads (Porites and other genera) that are sensitive to sea level changes with uncertainties of a few centimeters. Annual growth bands give time-series with relative errors of a few years and U-Th dating of the heads gives dates with errors of a decade. The magnitude of vertical deformation associated with earthquakes (paleoseismology) and deformation in intervals between earthquakes (paleogeodesy) are being determined from these data. Results are being modeled and historical earthquakes (seismograms from a variety of sources) are being used to determine if segment boundaries influenced dimensions of historical ruptures. The specific goals of this project are to: (1) better characterize source parameters of 1681, 1797, and 1833 events; (2) determine southern limit of these events; (3) extend record back to 14th century; (4) determine source characteristics of 1861 and 1907 quakes; (5) model historical seismograms of large quakes on Sumatran fault; (6) characterize aseismic strain events in 1861, 1797, and 1833 regions.