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: 2328485
• 负责人: Xiaowei Chen
• 金额: $ 39.94万
• 依托单位: Texas A&M University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-10-01 至 2025-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2328485&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.

该奖项是根据2021年《美国救援计划法》的全部或部分资助的（公共法117-2）。地震仍然是社会面临的最重要的自然危害之一。随着人类引起的地震性的增加，以前具有较低地震风险的地区（例如美国中部）现在面临着与地震相关的危害。在过去十年中，在美国中部以及加利福尼亚州和加利福尼亚州的改进仪器的地震速率急剧提高，为在两个截然不同的地质环境中提供了丰富的小型小型至中等尺寸地震的数据集；一种由大圣安德烈亚斯断层的构造运动主导，另一个是人类活动在不连续，较小的断层上引起地震。这为在两种环境中的控制因素和后果提供了更多了解的机会。通过研究和比较在两个非常不同的变形区域（北加州和俄克拉荷马州）中的地震及其相互作用，该项目将促进我们对地震物理学基本过程的理解，对构造环境的依赖，并帮助减少地震相关危害。对地震破裂过程与危害参数（地震性和地面运动）之间关系的理解有助于减少对当地社区和重要基础设施构成的地震危害。该分析还将结合地震和工业3D地震数据，这将有助于制定准则，以确定俄克拉荷马州潜在的危险危险压力。该项目包括在一系列级别上进行指导和协作，为两名研究生（在OU）的教育做出了贡献，并支持了早期职业PI（在OU）。地震目录，集群特征和源参数的最新数据库将为许多研究提供基本输入，并将引起地震危害社区的广泛关注，并了解地震物理学。方法和工作流程将涉足地震和探索地震学和结构地质学课程的活动。地震的复杂性是控制地震源动力学和随之而来的地面运动的重要因素，并且与地震发生的断层结构中的复杂性有关。该项目将使用高质量的地震图和工业3D地震数据，并开发改进的技术来量化复杂性并增强我们对各种时间和空间尺度上基本地震源过程的理解。研究人员专注于固有的地震源可变性，其与地质结构的关系及其对地震序列进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地震来源和地质断层结构进行了组合的光谱和时间结构域分析：北加利福尼亚州，由圣安德烈亚斯板块 - 边界断层和俄克拉荷马州主导，在低压率区域中，人类活动正在诱发人类活动诱发地震。光谱复杂性和源时间功能复杂性将被量化，并将开发自动分类方法以识别复杂的地震。共处的高分辨率工业3D地震数据和地震性使我们能够详细地理解地下室中地震故障的特征。多个数据集的综合和集成将有助于理解地质结构与地震破裂之间的互链链接。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估评估标准来通过评估来支持的。

项目成果

Influence of Fault Architecture on Induced Earthquake Sequence Evolution Revealed by High‐Resolution Focal Mechanism Solutions

• DOI: 10.1029/2022jb025040
• 发表时间: 2022-10
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: Yan Qin;Xiaowei Chen;Ting Chen;R. Abercrombie

Quantifying rupture characteristics of microearthquakes in the Parkfield Area using a high-resolution borehole network

使用高分辨率钻孔网络量化帕克菲尔德地区微地震的破裂特征

• DOI: 10.1093/gji/ggad023
• 发表时间: 2023
• 期刊: Geophysical Journal International
• 影响因子: 2.8
• 作者: Pennington, Colin N.;Wu, Qimin;Chen, Xiaowei;Abercrombie, Rachel E.
• 通讯作者: Abercrombie, Rachel E.