FESD Type I: Earthquake Fault System Dynamics

FESD I 型：地震故障系统动力学

• 批准号: 1135455
• 负责人: James Dieterich
• 金额: $ 465万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1135455&HistoricalAwards=false
• 关键词: FESD; Type; Earthquake; Fault; System

Great earthquakes occur at the boundaries of the world's tectonic plates where an increasing fraction of the population is exposed to high seismic risk. This project develops and uses large-scale computer simulations to investigate fault system interactions that control the occurrence and characteristics of earthquakes occurring along plate boundary fault systems. The project will develop computer models of the North American plate boundary, which consists of the subduction zone of Southern British Columbia, Washington, Oregon, and Northern California; and the San Andreas fault system of Northern and Southern California. This research addresses the short-term (minutes to years) predictibilty of earthquakes, and long-term processes (100-1000 years) that condition fault systems to fail in great earthquakes. To better characterize the magnitude and variability of ground shaking in damaging earthquakes, which is needed for increasing our resilience to earthquake disasters, the fault system models will be integrated with advanced ground motion simulations.The highly concentrated deformation of the brittle crust at plate boundaries largely occurs through the integrated slip of faults in geometrically complex fractal-like fault systems. Fault slip phenomena, including earthquakes, continuous fault creep, slow slip events, earthquake afterslip, and earthquake repeaters, with their exceptionally wide range of temporal and spatial scales, are products of the rich array of interactions that operate in these systems. The simulations of plate boundary fault systems developed by this project will span 10,000yrs of plate motion and consist of up to106 discrete events. Simulations on this scale are now possible due to advances in our understanding of fault constitutive properties and the interactions that give rise to the different modes of fault slip; growth of knowledge to define the 3D geometry of plate boundary fault systems; and development of numerical methods that permit highly efficient simulations across a very wide range of spatial and temporal scales. System-level simulations provide an experimental capability to probe these very complex systems to better understand the interactions that give rise to observable effects, and to advance predictive capabilities. In addition, simulations provide the means to integrate a wide range of observations from seismology, tectonic geodesy, and earthquake geology into a common framework. Probabilistic seismic hazard analysis (PSHA), the main tool used by earthquake scientists and engineers to ensure seismic safety in the built environment, requires long-term forecasting of ground motions of all potentially damaging earthquakes. This research will integrate the fault system models with advanced fault rupture and ground motion simulations to investigate the statistical nature of strong ground motions needed for reliable PSHA.

大地震发生在世界构造板块的边界上，其中越来越多的人口暴露于高地震风险。该项目开发并使用大规模的计算机模拟来研究控制沿板边界断层系统发生地震的发生和特征的故障系统相互作用。该项目将开发北美板块边界的计算机模型，该模型由不列颠哥伦比亚省南部，华盛顿，俄勒冈州和北加州的俯冲带组成；以及北加州和南加州的圣安德烈亚斯断层系统。这项研究解决了地震的短期（几分钟到几年）的预测，以及将断层系统在大地震中失败的长期过程（100-1000年）。为了更好地表征破坏性地震中地面摇动的幅度和可变性，这是提高我们对地震灾害的韧性所需的，这将与故障系统模型集成到高级地面运动模拟中。在板界，脆性壳的高度浓缩变形在很大程度上通过在类似于液体的易流化液体中的集成液体中的故障进行。断层滑移现象，包括地震，连续断层蠕变，慢速事件，地震后滑坡和地震中继器以及其异常范围的时间和空间尺度，是在这些系统中运行的丰富相互作用的产物。该项目开发的板边界断层系统的仿真将跨越10,000元的板运动，最高为106个离散事件。由于我们对故障本构属性的理解以及导致故障滑移模式的相互作用的理解的进步，现在可以在此量表上进行模拟。知识的增长以定义板边界断层系统的3D几何形状；并开发数值方法，这些方法允许在非常广泛的空间和时间尺度上进行高效的模拟。系统级模拟提供了实验能力来探测这些非常复杂的系统，以更好地了解产生可观察到的效果并提高预测能力的相互作用。此外，模拟还提供了将地震学，构造地质和地震地质学的广泛观察范围整合到一个共同框架中的各种方法。 概率地震危害分析（PSHA）是地震科学家和工程师用来确保在建筑环境中进行地震安全的主要工具，需要对所有潜在破坏性地震的地面运动进行长期预测。这项研究将将断层系统模型与高级断层破裂和地面运动模拟整合在一起，以研究可靠PSHA所需的强大地面运动的统计性质。