Studies in Western U.S. Geodynamics

知识价值：三个区域研究将解决在每个区域负责构造行为的过程。研究区域包括：1)南加州。重点研究圣安德烈亚斯断层转换断层环境下造山的成因；2)内华达山脉。研究将集中在圣安德烈亚斯断层和加州东部剪切带的边界构造强度，以及盆地和山脉的重力驱动扩张的性质；3)太平洋西北部。研究的重点是太平洋-北美相互作用作用下的剪切构造与俯冲边缘的相互作用，由弱挤压到强挤压。这些区域研究将以与板块尺度应力一致的方式进行建模，并将用于改进当前的板块尺度动态模型。所提出的研究将在二维和三维上完成，并采用有限元计算机模拟，以现实的方式将断层，粘性和塑性岩石变形机制以及重力驱动过程结合起来。这个项目将产生的结果将有助于理解板块相互作用和内部浮力驱动的大陆变形的相对重要性。此外，还将根据大地测量和地质断层数据，建立形变分布和速率的改进模型。这些结果将用于评估计算机模拟的质量和约束岩石圈强度。更广泛的影响：结果将有助于约束断层的强度和行为，这对理解地震过程很重要。该项目将通过合作、参与不同学科、将一系列研究结果整合为一致的结果，为研究生的未来做好准备。它还将有助于促进国际合作。

Intellectual Merit:Three regional studies will address the processes responsible for the tectonicbehavior in each region. The study areas are:1) Southern California. Study will focus on the cause of mountain building in thetransform-fault environment of the San Andreas fault;2) the Sierra Nevada. Study will focus on the tectonic strengths of the boundingSan Andreas fault and eastern California shear zone and on the nature of thegravitationally driven extension of the Basin and Range; and3) the Pacific Northwest. Study will focus on the interplay between the sheartectonics imposed by Pacific-North America interaction and the subduction margin,which varies from weakly to strongly compressive.These regional studies will be modeled in a manner consistent with plate scale stressesand will be used to improve the current plate scale dynamic model.The proposed research will be accomplished in two and three dimensions with a finiteelement computer simulations that incorporate faults, viscous and plastic rock deformationmechanisms, and gravity-driven processes in realistic ways.This project will produce results that will help to understand the relative importanceof plate interaction and internal buoyancy driven continental deformation.Also, improved models of the distribution and rate of deformation will be producedbased on geodetic and geologic faulting data. These results will be used both to evaluatethe quality of the computer simulations and to constrain lithospheric strength.Broader Impacts:Results will help constrain the strength and behavior of faults, which is important tounderstanding earthquake processes.This project will prepare a graduate student for the future through collaborations,participation in a diverse set of disciplines, and integration of the range of findingsinto consistent results. It also will help foster an international collaboration.