RAPID/Collaborative Research: Advancing Probabilistic Fault Displacement Hazard Assessments by Collecting Perishable Data from the 2023 Turkiye Earthquake Sequence

RAPID/合作研究：通过收集 2023 年土耳其地震序列的易腐烂数据推进概率断层位移危险评估

• 批准号: 2330152
• 负责人: Domniki Asimaki
• 金额: $ 5万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2330152&HistoricalAwards=false
• 关键词: RAPID; Collaborative; Research; Advancing; Probabilistic; RAPID; Collaborative; Research; Advancing; Probabilistic

The 300-km-long magnitude (M) 7.8 earthquake rupture along the East Anatolian Fault in Türkiye is one of the largest strike-slip ruptures instrumented globally. At the same time, the 150-km-long M7.5 rupture of the largest aftershock on the Sürgü fault, produced surface displacements on the order of 8 m, exceeding, on average, the displacement-length relations used for the 2023 National Seismic Hazard Model (NSHM) update by more than fifty percent. These ruptures share a similar tectonic setting with the San Andreas Fault System (SAFS) in California, so evaluating the NSHM by comparison with the Türkiye fault ruptures is important in the context of risk reduction in the US. A similar rupture on the SAFS, often referred to as 'The Big One' in California, will threaten the population and economy of major urban centers, national defense installations, and other critical infrastructures. Observing and documenting displacements along these exceedingly long and rare ruptures is therefore critical to understanding and reproducing earthquake rupture processes, empirically and numerically; to reducing uncertainty in regional hazard models; and reducing the risk of distributed infrastructure systems that are vital to the health and prosperity of communities, and vulnerable to ground deformation, such as water and gas pipelines. Findings and open-source datasets from this Grant for Rapid Response Research (RAPID) fieldwork will guide public policy and engineering design codes through future improvements of the NSHM, as well as decision makers for a greater extent of societal well-being and national defense. To complete this work, partnerships between academia and government agencies in both the US and Türkiye have been established; the team is diverse and includes a balance of early-career scientists and senior scientists, geotechnical earthquake engineers and earthquake geologists, US-based and in-country collaborators, and scientists from underrepresented backgrounds. The intellectual merit of this work lies in setting a new paradigm in fault rupture field mapping for engineering applications. While there is field, laboratory and numerical evidence that shallow geological conditions affect fault displacements, the evidence is at best qualitative, and thus the documented data cannot be integrated in engineering models for risk reduction. In order to capture these effects in predictive empirical models for engineering applications, new kind of dataset is needed that associates each fault displacement measurement site with geotechnical site characterization measurements. The primary field objectives include characterization of the 2023 ruptures by means of: (1) mapping the main fault rupture with high-resolution (cm-scale) GNSS surveys, photographs, ground-based lidar, and UAV-based terrain models, (2) documenting discrete and perishable offsets of cultural and geomorphic features, (3) characterizing the width and style of the deformation zone, (4) accompanying the measurements of the transient deformation zones with dynamic site characterization measurements on a sub-km scale using active source and ambient wavefield surface wave methods, along with horizontal to vertical spectral ratio (HVSR) measurements, (5) providing geological context (e.g., dominant geological processes and depositional units) for site characterization efforts, and (6) identifying secondary effects such as gravitational failures and liquefaction. Insights and scaling behaviors stemming directly from the field data will provide the first of what is envisioned to constitute the next-generation fault displacement datasets that will allow future PFDHA models to capture repeatable effects associated with local geologic conditions and fault geometry among other parameters.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.

300公里长的幅度（M）7.8沿Türkiye东部安纳托利亚断层的地震破裂是全球最大的滑滑破裂之一。同时，Sürgü断层上最大的余震的150​​公里长的M7.5破裂，在8 m的阶内产生了表面位移，平均超过了2023年国家地震危险模型（NSHM）使用的位移长度的更新超过50％。这些破裂与加利福尼亚州的San Andreas断层系统（SAFS）具有类似的构造环境，因此在美国降低风险的背景下，通过与Türkiye断层破裂进行了评估。 SAFS的类似破裂，通常称为加利福尼亚州的“大人物”，会威胁主要城市中心，国防设施和其他关键基础设施的人口和经济。因此，观察和记录沿这些极为漫长而罕见的破裂的位移对于急切和数值地理解和再现地震破裂过程至关重要。减少区域危害模型的不确定性；并降低对社区健康和繁荣至关重要的分布式基础设施系统的风险，并且容易受到地面变形的影响，例如水和天然气管道。这项赠款的发现和开源数据集用于快速响应研究（Rapid）实地研究将通过NSHM的未来改进来指导公共政策和工程设计代码，并在更大程度上进行社会福祉和国防。为了完成这项工作，已经建立了学术界和政府机构之间的伙伴关系；该团队是多样的，包括早期职业科学家和高级科学家，岩土技术工程师和地震地质学家，美国和国内合作者的平衡，以及来自代表性不足的背景的科学家。这项工作的智力优点在于为工程应用程序设置新的故障破裂场映射。尽管存在浅层地质条件影响故障位移的现场，实验室和数值证据，但证据充其量是定性的，因此，记录的数据不能集成到工程模型中以降低风险。为了在工程应用的预测经验模型中捕获这些效果，需要使用新型的数据集将每个故障位移测量站点与岩土工艺位点表征测量相关联。主要场对象包括通过以下方式进行2023破裂的表征：使用主动源和环境波场表面波方法以及水平与垂直频谱比（HVSR）测量值（5）提供地理环境（例如，范围范围的粒料和位置范围），识别粒料和次数的特征（6），使用了水平与垂直频谱比率（5），对垂直频谱的测量（5），使用主流的地理过程和次数的特征（6）识别（6）识别（6）识别（6）识别（6）液化。直接源自现场数据的见解和缩放行为将提供构成下一代故障位移数据的设想的第一个数据集，这些数据将使未来的PFDHA模型能够捕获与当地地质条件和其他参数相关的可重复效应，并在其他参数之间进行裁决，这反映了NSF的法定任务和诚实的支持，这是由诚实的构成的依据来评估。