Collaborative Research: Exploring System-Wide Events on Complex Fault Networks using Fully-Dynamic 3D Earthquake Cycle Simulations

协作研究：使用全动态 3D 地震周期模拟探索复杂故障网络上的系统范围事件

基本信息

批准号：
2053372
负责人：
Brittany Erickson
金额：
$ 34.69万
依托单位：
University of Oregon Eugene
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：
2021-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2053372&HistoricalAwards=false
关键词：
Collaborative Research Exploring System Wide

项目摘要

The world’s largest earthquakes occur on interconnected fault networks embedded in the Earth’s crust. The conditions under which large earthquakes occur is believed to be dependent on a millennia-long history of tectonic motion in the region, as well as other physical conditions such as frictional forces acting on the fault itself. The goal of this work is to use mathematical modeling to expand our understanding of the physics that dictate where and when an earthquake will occur. The high computational cost associated with simulating long periods of earthquake activity has limited previous modeling attempts to simple scenarios (for example, considering only a single fault, with no generation of damaging seismic waves). The PIs will overcome these limitations by using a high-performance implementation of their recently developed advanced numerical scheme for earthquake cycles. Key questions the researchers will explore include: why do some large earthquakes occur on faults that seem stable when subjected to tectonic loading? Results from these studies will improve seismic hazard estimates by shedding light on if and how such large earthquakes can occur on a given fault network. The codes will be made publicly available under a permissive open source license for use by others. In addition to supporting one junior faculty member (under-represented in her field) and one mid-career faculty member, the proposal supports the mentoring of two graduate students in interdisciplinary research.The goal of this work is to expand understanding of the physical settings in which system-wide earthquakes can occur through the use of large-scale, physically-robust earthquake cycle models. This work will develop a large-scale, high-performance framework that accounts for complex fault geometries, off-fault material properties, and full dynamics in 3D volumes. The method will couple interseismic loading with coseismic rupture and wave propagation in a self-consistent manner. The coupled approach will be used to explore the role that tectonic loading, rupture history, fault geometry and other physical features play in system-wide failure of fault networks. This will include such studies as the keystone fault hypothesis, namely, that faults in a system that are optimally oriented with respect to the regional stress field are stabilized by misoriented keystone faults until the entire network is primed to fail. The high computational cost associated with simulating the interseismic period has limited previous cycle models to simple fault geometries, suppressed dynamic effects, and/or use small simulation volumes. The project will use recently developed hybridized scheme for the interseismic period, which is well suited for problems that in the past have been too computationally expensive. The hybrid method will be coupled with a newly developed technique for dynamic rupture simulation to study sequences of multiple earthquakes on complex fault networks. By leveraging state-of-the-art algorithms and high-performance computing, this work will lead to the development of a large-scale, physically robust, predictive modeling framework of earthquake source processes on complex fault networks. This new framework will allow the exploration of fundamental questions in earthquake science, focusing on how earthquakes can nucleate on misoriented faults, often giving rise to huge, network-wide events. The 2010 Mw 7.2 El Mayor-Cucapah and the 2016 Mw 7.8 Kaikoura are two well-known examples of earthquakes whose magnitudes exceeded expectations by cascading through multiple segments of a fault network. This work will contribute to seismic hazard estimates by calculating event probabilities associated with complex fault networks in a physically robust modeling environment, complementing and improving the greater efforts of the earthquake simulators currently used to inform earthquake forecasting. In order to benefit the larger earthquake science community the PIs will make the developed codes publicly available under the MIT license, and will use an open development strategy.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.

世界上最大的地震发生在地壳中嵌入的互连断层网络上。人们认为，发生大地震的条件取决于该地区千年的构造运动历史以及其他物理状况，例如作用于断层本身的摩擦力。这项工作的目的是使用数学建模来扩展我们对决定地震何时何时发生的物理学的理解。与模拟长时间地震活动相关的高计算成本的高度计算成本有限于以前的建模尝试（例如，仅考虑一个单一故障，没有产生破坏性的地震波）。 PI将通过使用其最近开发的地震周期的高级数值方案来克服这些局限性。研究人员将探讨的关键问题包括：为什么在经过构造负载时似乎稳定的断层发生了一些大地震？这些研究的结果将通过阐明在给定的断层网络上是否以及如何发生如此大的地震来改善地震危害估计。这些代码将根据允许的开源许可证公开提供，以供他人使用。该提案除了支持一名初级教职员工（在她的领域中代表性不足）和一名职业职业教师外，还支持两名研究生在跨学科研究中的心理。这项工作的目的是扩大对物理环境的理解，从而通过使用大型，物理上的地震来实现系统范围的地震，从而实现大小，物理上的地震模型。这项工作将开发出一个大规模的高性能框架，该框架构成了复杂的故障几何形状，OFFEART材料属性和3D卷中的完整动态。该方法将以自洽的方式将微区载荷与coseis震动破裂和波传播。耦合方法将用于探索构造加载，破裂历史，故障几何形状和其他物理特征在故障网络的全系统故障中起作用的作用。这将包括诸如Keystone断层假说，即，在与区域应力场相对于区域应力场最佳取向的系统中的故障稳定在不良导向的基石断层之前，直到整个网络都无法失败为止。与模拟跨界时期相关的高计算成本将以前的周期模型限制在简单的故障几何形状，抑制动态效应和/或使用少量模拟体积上。该项目将在跨界时期使用最近开发的杂交方案，该方案非常适合过去的计算太昂贵的问题。混合方法将与新开发的动态破裂模拟技术相结合，以研究复杂断层网络上多个地震的序列。通过利用最新的算法和高性能计算，这项工作将导致在复杂故障网络上的地震源过程的大规模，身体健壮，预测性建模框架的发展。这个新的框架将允许对地震科学中的基本问题进行探索，重点关注地震如何在不良导向的断层上进行核核，这通常会引起巨大的全网络事件。 2010年MW 7.2 El Mayor-Cucapah和2016 MW 7.8 Kaikoura是两个众所周知的地震例子，通过通过故障网络的多个细分市场级联，其命中超出了预期。这项工作将通过在物理强大的建模环境中计算与复杂故障网络相关的事件可能性，从而有助于地震危险估计，从而完成并改善目前用于告知地震预测的地震模拟器的更大努力。为了使更大的地震科学界受益，PIS将使开发的法规公开获得，并将使用开放的开发策略。该奖项反映了NSF的法定任务，并通过使用该基金会的知识分子的优点和更广泛的影响来审查标准，认为NSF的法定任务被认为是宝贵的支持。