ER-PF: Using Distributed Acoustic Sensing for Tremor Detection and Site Characterization in Cascadia to Evaluate Earthquake Hazard

ER-PF：使用分布式声学传感进行卡斯卡迪亚的震颤检测和场地表征，以评估地震危险

• 批准号: 2053085
• 负责人: Manuel Mendoza
• 金额: $ 17.4万
• 依托单位: Mendoza, Manuel Matthew
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2053085&HistoricalAwards=false
• 关键词: ER; PF; Using; Distributed; Acoustic; ER; PF; Using; Distributed; Acoustic

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Dr. Manuel Mendoza has been granted an EAR Postdoctoral Fellowship to carry out research and education plans at University of Colorado Boulder and Colorado School of Mines. Dr. Mendoza plans to develop a new technique for earthquake monitoring called distributed acoustic sensing (DAS). DAS uses dark (unlit/unused) existing telecommunication fiber optic cables and turns them into an instrument that acts as a network capable of detecting tiny or distant seismic (earthquake) events. In the Pacific Northwest of the US where two tectonic plates converge, the conditions are right for large earthquakes which could result in other hazards such as tsunamis. Therefore, large-scale and continuous seismic monitoring is needed to evaluate the impending risks. In this project, Dr. Mendoza will work alongside Professors Anne Sheehan and Dr. Ge Jin to test and demonstrate DAS performance capabilities by carrying out a DAS experiment in Northwestern Washington. Specifically, the work will investigate seismic events known as “tremor” and determine how local geologic conditions vary along the fiber cable. Dr. Mendoza’s work will advance understanding of earthquakes, how the ground shakes in response to them, and consequent seismic hazards. The proposed study will provide opportunities for DAS to be applied at larger scales alongside existing seismic networks to perform multi and interdisciplinary research and monitoring of Earth processes. The project will also allow Dr. Mendoza to teach and mentor students from underrepresented groups, including as a mentor on the Diversity, Inclusion, and Access committee at the Colorado School of Mines and as a summer internship mentor at University of Colorado Boulder. Other activities associated with this project include designing and leading a local DAS experiment for a geophysics course and supervising the professional and educational development of an undergraduate student who will conduct original research with the DAS data. At both campuses, the PI will engage in outreach activities aimed at increasing public scientific literacy and broadening participation in the S.T.E.M fields.Distributed acoustic sensing (DAS) using fiber-optics to measure deformation (strain) caused by seismic perturbations in the Earth has, in recent years, proved to be a highly applicable and promising tool in seismology. This is owed to its ability to be configured as a seismic array with an aperture on the order of tens of kilometers, meter-level sensor (i.e. channel) spacing, and performance comparable to that of conventional broadband seismometers. This implies that DAS arrays can blanket a large area while not suffering from spatial aliasing when sampling the seismic wavefield – unlike traditional networks – and provide new information in high fidelity that often goes missed. A single DAS experiment can therefore be used to simultaneously investigate a variety of Earth processes occurring across different spatial and temporal scales. Here, the investigators will conduct the first known DAS experiment in Cascadia using fiber from an existing telecommunication cable, to monitor tremor and characterize site conditions for the purpose of evaluating seismic hazard. Specifically, the PI will pursue three primary scientific goals: (1) Use DAS to detect and locate tremor in Cascadia; (2) characterize its spatiotemporal behavior and infer its contribution to stressing the up-dip locked portion of the plate interface; and (3) determine meter-level variation in site conditions along the DAS array. These goals will be addressed by employing seismic array-based techniques such as beamforming and beam back-projection to capture tremor, as well as ambient noise interferometry techniques to estimate shear wave velocities of the top 30 meters (Vs30). The results obtained from this study will be compared to other observations performed using different instruments and methods, to demonstrate the efficacy of DAS in improving earthquake and ground shaking models in Cascadia and assess its implications for future experiments in a variety of tectonic settings.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.

该裁决是根据2021年《美国救援计划法》（公法117-2）.dr的全部或部分资助的。曼努埃尔·门多萨（Manuel Mendoza）被授予耳朵博士后奖学金，以在科罗拉多大学博尔德大学和科罗拉多州矿业学院进行研究和教育计划。 Mendoza计划开发一种用于地震监测的新技术，称为分布式声传感（DAS）。DAS使用黑暗（未使用/未使用的）现有的电信光纤电缆，并将它们变成一种能够检测微小或远距离的地震（地震）事件的网络。在美国西北太平洋，两个构造板汇聚在一起，适合大地震的条件，这可能导致其他危害，例如海啸。因此，需要进行大规模和连续的地震监测来评估即将到来的风险。在这个项目中，门多萨博士将与教授安妮·希恩（Anne Sheehan）和盖金（Ge Jin）博士一起工作，通过在华盛顿西北部进行DAS实验来测试和演示DAS性能能力。具体而言，这项工作将调查称为“震颤”的地震事件，并确定局部地质条件在纤维电缆上的变化。门多萨（Mendoza）博士的工作将提高人们对地震的理解，地面如何响应它们以及随之而来的地震危害。拟议的研究将为DA与现有的地震网络一起在更大范围内应用DA，以进行多学科和跨学科研究以及对地球过程的监测。该项目还将允许Mendoza博士教育和指导来自代表性不足的团体的学生，包括科罗拉多州矿业学院的多样性，包容性和访问委员会的心理，以及科罗拉多大学科罗拉多大学的暑期实习导师。与该项目相关的其他活动包括设计和领导当地的DAS实验，以进行地球物理课程，并监督本科生的专业和教育发展，该学生将使用DAS数据进行原始研究。在这两个校园中，PI将进行外展活动，旨在增加公共科学素养，并扩大参与S.T.E.M田间的参与。使用光纤镜来衡量的声音传感（DAS），以衡量由地球上的扰动引起的地震扰动引起的变形（应变），近年来已经证明是一种高度适用的应用程序，并且是一种高度适用的工具。这是由于其能够被配置为具有数十公里，仪表级传感器（即通道）间距的孔的地震阵列的能力，并且性能与传统的宽带地震仪相当。这意味着DAS阵列可以在抽样地震波场（与传统网络不同）时覆盖大面积，而在采样地震波场时不会遭受空间混叠，并提供了通常会丢失的高忠诚度的新信息。因此，单个DAS实验可用于同时研究在不同的空间和临时尺度上发生的各种地球过程。在这里，研究人员将使用现有的电信电缆中的光纤在卡斯卡迪亚进行第一个已知的DAS实验，以监测震颤并表征现场条件，以评估地震危险。具体而言，PI将追求三个主要的科学目标：（1）使用DAS检测和定位在卡斯卡迪亚的分支； （2）表征其时空行为，并推断其对强调板界面的上锁定部分的贡献； （3）确定沿DAS阵列的站点条件下的仪表级变化。这些目标将通过采用基于地震阵列的技术（例如光束形成和横梁向后投影）来解决捕获树，以及环境噪声干扰技术来估计前30米的剪切波速度（VS30）。将从这项研究中获得的结果将与使用不同工具和方法进行的其他观察结果进行比较，以证明DA在改善卡斯卡迪亚的地震和地面摇动模型中的效率，并评估其对各种构造环境中未来实验的影响。这种奖项通过评估官员的构成范围，反映了NSF的诚实范围，以反映诚实的支持者的构成师的构成师。