Three-dimensional modeling of interseismic, co-seismic, and post-seismic deformation in Taiwan

台湾震间、同震和震后形变的三维建模

• 批准号: 0537625
• 负责人: Mark Simons
• 金额: $ 20万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-15 至 2009-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0537625&HistoricalAwards=false
• 关键词: Three; dimensional; modeling; interseismic; co

Currently, crustal dynamics lacks internally consistent continuum models that explain observations spanning the entire earthquake cycle including, the interseismic, coseismic, and postseismic periods, while being consistent with the longer timescale strain manifest in the geology, such as the distribution of topographic relief. Studies of the earthquake cycle in Taiwan are somewhat unique because of the high strain rates over all three phases of the earthquake cycle and the extraordinary geodetic coverage before, during, and after the 1999 Mw 7.6 Chi-Chi earthquake. In addition the geometry of the primary faults structures is now relatively well known and reasonably reliable estimates of 3D variations in material properties are becoming available.Our effort aims to build a single model that addresses both the misfits of existing models to their respective data sets, while at the same time trying to derive an internally consistent description that works up to time scales involving the building of the mountains. We are addressing the following tasks in approximately this order: 1) Revise elastic coseismic and afterslip models for the 1999 Mw 7.6 Chi-Chi earthquake using 3D elastic structures and a new fault geometry. These models will consider all available GPS, SAR, and optical geodetic data. 2) Construct an initial suite of 2-D visco-elasto-plastic models to develop intuition for spin-up issues, as well as effects of different boundary conditions. 3) Construct 3D post-seismic and interseismic visco-elasto-plastic models. 4) Consider observationally constrained thermal controls on rheology - as well as the role of erosion in modifying the long-term evolution of mountain range.This projects aims to develop an internally consistent geodynamic model spanning time scales from earthquakes up to that of mountain building. It takes advantage of, and contributes to, state-of-the-art geodetic and modeling tools to address the inherently difficult problem of laterally varying rheological structures both on major faults and in the surrounding media. All analysis tools being developed as part of this project are released to the public. This activity forms part of a larger collaboration with scientists in the U.S. and Taiwan. We expect that this effort will result in a better understanding of seismic potential in Taiwan.

目前，地壳动力学缺乏内部一致的连续模型，解释观测跨越整个地震周期，包括，地震间，同震，和震后时期，而符合较长的时间尺度应变表现在地质，如地形起伏的分布。 台湾地震周期的研究有些独特，因为在地震周期的所有三个阶段的高应变率和非凡的大地测量覆盖之前，期间和之后的1999年Mw7.6集集地震。 此外，几何的主要断层结构是现在相对众所周知的和合理可靠的估计的3D变化的材料properties变得available. We的努力旨在建立一个单一的模型，既解决现有的模型，以各自的数据集的不匹配，而在同一时间试图获得一个内部一致的描述，工作到涉及建设的山的时间尺度。我们正在解决以下任务，大约在这个顺序：1）修改弹性同震和后滑模型，1999年Mw7.6集集地震使用三维弹性结构和一个新的断层几何。 这些模型将考虑所有现有的全球定位系统、合成孔径雷达和光学大地测量数据。 2)建立一套初始的二维粘弹塑性模型，以直观地了解旋转问题以及不同边界条件的影响。 3)建立三维震后和震间粘弹塑性模型。 4)考虑到流变学的观测约束热控制-以及侵蚀在改变山脉长期演变中的作用，该项目旨在开发一个内部一致的地球动力学模型，其时间跨度从地震到造山运动。 它利用，并有助于，国家的最先进的大地测量和建模工具，以解决内在的困难问题，横向变化的流变结构的主要故障和周围的介质。 作为该项目一部分开发的所有分析工具都向公众发布。 这项活动是与美国和台湾科学家更大合作的一部分。 我们期望这项工作将导致更好地了解台湾的地震潜力。