Dynamics and Kinematics of North America -Juan de Fuca- Pacific Plate Interaction: Constraints from GPS Geodesy and Geophysical Modeling

北美的动力学和运动学 -Juan de Fuca-太平洋板块相互作用：来自 GPS 大地测量学和地球物理建模的约束

• 批准号: 0003483
• 负责人: M. Meghan Miller
• 金额: $ 4.3万
• 依托单位: Central Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-01-15 至 2002-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0003483&HistoricalAwards=false
• 关键词: Dynamics; Kinematics; North; America; Juan

EAR-0003483Miller Characterizing North American continental dynamics critically depends on constraining Pacific Northwest tectonics. The Pacific Northwest provides key constraints that differentiate dynamic models of active deformation in western North America at a plate boundary scale. The San Andreas system, entrainment of the Sierra Nevada block, and the role of modern Basin and Range extension in plate interaction and within-plate tectonics, cannot be accurately understood in ignorance of this region. Moreover, Cascadia is a global class natural laboratory for testing and comparing subduction zone interseismic strain accumulation models, models that are widely applied to other subduction zones where such testing is precluded by natural complexity. Unique paleoseismic constraints on a single, large-magnitude and relatively simple, margin-wide rupture of the 1700 A.D. subduction zone event make Cascadia an excellent case study of viscoelastic vs. elastic deformation models 300 years into the interseismic cycle. Rarely is such a simple system, of such vintage, so well known. The proposed continuation of geodetic and geophysical modeling studies will place first order constraints on crustal deformation in the Pacific Northwest, where they have direct implications for subduction zone mechanics and for continental dynamics, as well as for plate driving forces. These studies also directly support seismic risk evaluation in the urban corridor from Puget Sound to Portland, Oregon. The investigators will undertake completion of the PANGA velocity field and completion of dislocation modeling, as well as continued operation of the continuous PANGA GPS network. Meeting these goals requires ongoing observations by the PANGA array, setting these results results in the context of other western U.S. deformation arrays, continuing the regional kinematic and dynamic modeling studies, and refining recent models for subduction zone dynamics. This approach will resolve the superimposed interseismic (elastic and viscoelastic) subduction strain field from the regional secular stain field well enough to address the kinematic and dynamic models.

描述北美大陆动力学的特征主要取决于太平洋西北构造的约束。太平洋西北地区提供了关键的限制，区分在板块边界尺度上的北美西部活动变形的动态模型。圣安德烈亚斯系统，夹带的塞拉利昂内华达州块，和现代盆地和山脉的延伸在板块相互作用和板块内构造的作用，不能准确地理解在这个地区的无知。此外，卡斯卡迪亚是一个全球级的天然实验室，用于测试和比较俯冲带地震间应变积累模型，这些模型被广泛应用于其他俯冲带，这些测试因自然复杂性而无法进行。独特的古地震约束的一个单一的，大规模的和相对简单的，边缘范围内的破裂1700年的俯冲带事件使卡斯卡迪亚一个很好的案例研究粘弹性与弹性变形模型300年的地震周期。很少有这样一个简单的系统，如此古老，如此众所周知。拟议继续进行的大地测量和地球物理模拟研究将对太平洋西北部的地壳变形施加一级约束，这些约束对俯冲带力学和大陆动力学以及板块驱动力具有直接影响。这些研究还直接支持从普吉特海湾到俄勒冈州波特兰的城市走廊的地震风险评估。研究人员将完成PANGA速度场和位错建模的完成，以及连续PANGA GPS网络的继续运行。实现这些目标需要PANGA阵列进行持续观测，将这些结果与美国西部其他变形阵列相结合，继续进行区域运动学和动力学建模研究，并改进俯冲带动力学的最新模型。这种方法将解决叠加的地震间（弹性和粘弹性）俯冲应变场的区域长期应变场以及足以解决运动学和动力学模型。