Collaborative Research: Roles of rupture complexity, geological structure, stress interaction on earthquake sequences

合作研究：破裂复杂性、地质结构、应力相互作用对地震序列的作用

• 批准号: 2043064
• 负责人: Xiaowei Chen
• 金额: $ 39.94万
• 依托单位: University of Oklahoma Norman Campus
• 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 2023-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2043064&HistoricalAwards=false
• 关键词: Collaborative; Research; Roles; rupture; complexity

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Earthquakes remain one of the most significant natural hazards facing society. With the increase of human-induced seismicity, regions that previously had lower seismic risk (e.g., central United States) are now facing earthquake-related hazards. The dramatic increase in the seismicity rate during the past decade in central US, and the improved instrumentation here and in California provide a rich dataset of well-recorded small-to-moderate sized earthquakes in two very different geologic settings; one dominated by tectonic motion on the great San Andreas fault, and the other where human activities induced earthquakes on less continuous, smaller, faults. This provides the opportunity to learn more about the controlling factors and consequences of earthquakes in both settings. By studying and comparing the earthquakes and their interactions in two very differently deforming regions (Northern California and Oklahoma), this project will advance our understanding of the fundamental processes of earthquake physics, their dependence on tectonic setting, and help reduce earthquake related hazards. An improvement in understanding of the relationship between earthquake rupture processes and hazard parameters (seismicity and ground motion) could help to reduce seismic hazard posed to local communities and important infrastructure. This analysis will also combine earthquake and industry 3D seismic data, which will help to develop guidelines to identify potentially hazardous critically stressed faults in Oklahoma. The project includes mentoring and collaboration on a range of levels, contributing to the education of two graduate students (at OU) and support for an early-career PI (at OU). The derived state-of-the-art database of earthquake catalog, cluster characteristics and source parameters will provide fundamental input for many studies, and will be of broad interest to earthquake hazard community, and understanding of earthquake physics. The methods and workflow will feed into activities for classes in earthquake and exploration seismology, and structural geology. The complexity of earthquakes is a significant factor governing earthquake source dynamics and the consequent ground motions, and it is related to complexity in the fault structures on which the earthquakes occur. This project will use both high-quality earthquake seismograms and industrial 3D seismic data, and develop improved techniques to quantify complexity and enhance our understanding of the fundamental earthquake source process on a variety of temporal and spatial scales. The researchers focus on the inherent earthquake source variability, its relationship with geologic structure, and its influence on earthquake sequence evolution and ground motion patterns. They perform a combined spectral and time domain analysis of earthquake sources and geological fault structure in two distinct tectonic settings: northern California which is dominated by the San Andreas plate-boundary fault, and Oklahoma where human activities are inducing earthquakes in a low-strain rate region. Spectral complexity and source-time-function complexity will be quantified, and automatic classification methods will be developed to identify complex earthquakes. Collocated high-resolution industrial 3D seismic data and seismicity enables us to better understand characteristics of seismogenic faults in the basement in detail. The synthesis and integration of multiple datasets will help to understand the interlink between geologic structure and earthquake rupture.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.

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公法117-2)。地震仍然是社会面临的最严重的自然灾害之一。随着人为地震活动的增加，以前地震风险较低的地区(如美国中部)现在正面临与地震有关的危险。过去十年美国中部地震活动率的急剧增加，以及这里和加利福尼亚州改进的仪器设备，提供了在两个截然不同的地质环境中记录良好的中小型地震的丰富数据集；一个以圣安德烈亚斯大断层上的构造运动为主，另一个是人类活动在不太连续的较小断层上诱发地震。这为在这两种情况下更多地了解地震的控制因素和后果提供了机会。通过研究和比较两个形变差异很大的地区(加利福尼亚州北部和俄克拉何马州)的地震及其相互作用，该项目将增进我们对地震物理基本过程及其对构造环境的依赖的理解，并有助于减少与地震有关的灾害。增进对地震破裂过程与灾害参数(地震活动和地面运动)之间关系的了解，可有助于减少对当地社区和重要基础设施造成的地震灾害。这项分析还将结合地震和工业3D地震数据，这将有助于制定指导方针，以识别俄克拉荷马州潜在的危险严重应力断层。该项目包括在一系列层面上的指导和合作，有助于教育两名研究生(在OU)和支持职业生涯早期的PI(在OU)。得到的最先进的地震目录、震群特征和震源参数数据库将为许多研究提供基本输入，并将对地震危险界和地震物理学的理解产生广泛的兴趣。这些方法和工作流程将用于地震和勘探地震学以及构造地质学的课程活动。地震的复杂性是控制震源动力学和随之而来的地面运动的一个重要因素，它与发生地震的断层结构的复杂性有关。该项目将使用高质量的地震地震图和工业3D地震数据，并开发改进的技术来量化复杂性，并加强我们对各种时间和空间尺度上的基本震源过程的理解。研究人员重点研究了震源的内在变异性及其与地质构造的关系，以及它对地震序列演化和地面运动模式的影响。他们在两个不同的构造环境中对震源和地质断层结构进行了联合频谱和时间域分析：加利福尼亚州北部以圣安德烈亚斯板块边界断层为主，俄克拉何马州人类活动在低应变率地区诱发地震。光谱复杂性和震源-时间-函数复杂性将被量化，并将开发自动分类方法来识别复杂地震。搭配高分辨率工业三维地震资料和地震活动性，使我们能够更详细地了解基底发震断裂的特征。综合和整合多个数据集将有助于了解地质结构和地震破裂之间的相互联系。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。