Recovery of Material Parameters and Friction Laws Associated with Earthquakes, Interseismic Slip, and Tidal Deformation

恢复与地震、震间滑移和潮汐变形相关的材料参数和摩擦定律

基本信息

批准号：
2108175
负责人：
Maarten de Hoop
金额：
$ 20.8万
依托单位：
William Marsh Rice University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2108175&HistoricalAwards=false
关键词：
Recovery Material Parameters Friction Laws

项目摘要

The study of earthquake physics remains highly challenging because of its complex dynamics and multifaceted nature. This research takes on the challenge of mitigating the impacts of earthquakes through mathematical understanding. It holds the promise of producing fundamentally new insights in fault physics and advancing the knowledge of friction laws, nucleation and rupture dynamics, localization of (micro)seismicity, crustal rheology, and monitoring stress and material properties. Determining the friction during an earthquake is required to understand when and where earthquakes occur. While this case cannot be reasonably studied in isolation, it is a central thrust of the research. A study of earthquake physics comprises nonlinear (segmented) fault dynamics, formulated as an inverse problem. Faults have nontrivial geometry, dependent on material properties of juxtaposed crustal blocks changing in time, stress, and general rheology of Earth’s crust and upper mantle and large-scale deformation. Tidal forcing will be exploited to enable the study of buoyancy structure deep in our planet's interior. Results will yield procedures for monitoring and obtaining invaluable information about rheology and microstructure in the subsurface, which could also be employed in geothermal exploration and carbon dioxide sequestration. The project offers, via collaborations, a unique interdisciplinary educational experience for the students giving them a much broader appreciation of the importance of novel techniques and real-life implications. The investigator will study inverse problems associated with earthquakes, interseismic slip, and tidal deformation. These inverse problems are defined through systems of partial differential equations describing elastic-gravitational deformation and waves, coupled to nonlinear rate- and state-dependent friction laws on faults, as well as extensions to viscoelastic and nonlocal elastic behaviors accounting for microstructure and complex rheologies. The key advances will pertain to determining friction during an earthquake, gleaning information about friction laws on faults also during interseismic deformation, in conjunction with recovering anisotropic elastic / viscoelastic / nonlocal-elastic material parameters in the crust and fault zones exploiting ruptures, dislocation, and microseismic clouds as sources as well as tidal forcing of the Moon. The rigorous study of possible rapid recovery of a moment tensor (earthquake magnitude and focal mechanism for early warning) from prompt elastogravity signals will be included in the analysis.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

地震物理学的研究由于其复杂的动态和多方面的性质而仍然是高度挑战性的。这项研究面临着通过数学理解来减轻地震的影响的挑战。它具有从根本上对断层物理学产生新的见解，并促进摩擦法律，核和破裂动态的知识，（微）地震性，地壳流变学以及监测压力和物质特性的局部化。需要在地震期间确定摩擦才能了解地震何时何地发生。尽管不能孤立地合理地研究此情况，但它是研究的中心作用。对地震物理学的研究包括非线性（分段）断层动力学，该动力学被认为是一个反问题。断层具有非平凡的几何形状，取决于与地壳和上地幔和大规模变形的时间，压力和一般流变的并置的地壳块的材料特性变化。潮汐强迫将被利用，以使我们地球内部深处的浮力结构进行研究。结果将产生监测和获取有关地下流变学和微观结构的宝贵信息的程序，该信息也可以用于地热探索和二氧化碳隔离中。通过合作，该项目为学生提供了独特的跨学科教育经验，使他们对新技术和现实生活的重要性有了更广泛的了解。研究人员将研究与地震，经济震荡和潮汐变形有关的反问题。这些反问题是通过描述弹性 - 重大变形和波浪的部分微分方程的系统来定义的，这些系统与非线性速率和状态依赖性摩擦法相结合，以及对粘弹性和非局部弹性行为的扩展，这些弹性和非局部弹性行为占微观结构和复杂的流变。 The key advances will pertain to determine friction during an earthquake, gleaning information about friction laws on faults also during interseismic deformation, in conjunction with recovering anisotropic elastic / viscoelastic / nonlocal-elastic material parameters in the crust and fault zones exploiting ruptures, dislocation, and microseismic clouds as sources as well as tidal forcing of the Moon.分析将包括迅速的弹性信号的矩张量（地震幅度和焦点机制）可能快速恢复的严格研究。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛影响的审查标准来评估，认为NSF的法定任务被认为是珍贵的支持。