Collaborative Research: HIPER - 3D Onshore-Offshore Imaging of Controls on Subduction Zone Megathrust Rupture and Slip Behavior

合作研究：HIPER - 俯冲带巨型逆冲断裂和滑动行为控制的 3D 陆上-海上成像

• 批准号: 1951202
• 负责人: Susan Beck
• 金额: $ 25.3万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-15 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1951202&HistoricalAwards=false
• 关键词: Collaborative; Research; HIPER; 3D; Onshore

The largest earthquakes worldwide occur in subduction zones where the tectonic plates associated with ocean basins descend into Earth’s interior. These earthquakes occur on large faults that separate the descending oceanic plate from the overlying continental plate. Ground shaking from these earthquakes have significant human and economic impacts. Subduction zone earthquakes that rupture the seafloor can generate tsunamis that cause additional destruction. Regions of the world at risk from these earthquakes include the U.S. Pacific Northwest and Alaska, Central and South America, Japan, and Southeast Asia. Here, the researchers deploy a dense array of seismometers to image at high resolution a portion of the subduction zone that ruptured offshore northern Ecuador in a large earthquake in 2016. The project leverages data acquisition from an offshore and onshore deployment supported by European funding agencies. Analysis of the data provides an opportunity to link variations in structure and seismic properties along the subduction zone to the distribution of slip behaviors that culminates in large earthquakes. Results from this research improve seismic hazard assessment near subduction zones. The project also provides support for a graduate student in seismology and training of undergraduate students.High resolution studies of subduction zones reveal their complexity and diversity of structure and physical properties. Heterogeneity downdip and along strike influences plate coupling and slip behavior on the plate interface, as well as in the downgoing plate and in the upper plate, which ultimately culminates in large magnitude earthquakes. The HIPER project (High Resolution Imaging of the Pedernales Earthquake Rupture Zone) is supported by French and German funding agencies. It acquires active and passive offshore-onshore seismic data along the northern Ecuador subduction zone in and adjacent to the 2016 Mw 7.8 Pedernales rupture. The HIPER project includes 60 ocean-bottom seismometers and 150 land stations that record active source shots from a 3D grid, followed by passive recording of earthquakes. Here, the U.S. team complete the project by deploying a dense array of 3-component short period nodes (~300) and 60 broadband sensors. The goal is to significantly densify the onshore portion of HIPER for active source recording. It also widens the aperture of passive recording to improve lateral coverage and imaging at depth. The combined arrays present an exceptional opportunity for multiscale 3D imaging and examine the relationship between structure, fluids, and variations in slip behavior from seismic to aseismic. Ultimately, it allows to reconcile observations from geodesy and seismology with geology, structure, and seismicity. Data analysis employs machine learning generalized phase detection to significantly increase source detection. It also involves a combination of traveltime and ambient noise tomography, and high frequency receiver functions as input to a multi-step series of inversions to constrain earthquake locations and seismic structure along and above the seismogenic zone.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.

全世界最大的地震发生在俯冲带中，在俯冲带中，与海洋贝斯相关的构造板降落在地球内部。这些地震发生在大断层上，将下降的海洋板与上覆的连续板分开。这些地震的地面颤抖具有重大的人类和经济影响。破裂海底破裂的俯冲带可能会产生造成额外破坏的海啸。来自这些地震的世界风险地区包括美国太平洋西北部和阿拉斯加，中部和南美，日本和东南亚。在这里，研究人员部署了一系列密集的地震仪，以在高分辨率的一部分俯冲带的一部分，该区域的一部分在2016年的一次大地震中破裂了北厄瓜多尔北部的北部厄瓜多尔。该项目利用欧洲资助机构支持的离岸和陆上部署的项目获取数据获取。数据分析提供了一个机会，可以将俯冲带的结构和地震特性的变化与在大地震中达到顶点的滑移行为的分布联系起来。这项研究的结果改善了俯冲带附近的地震危险评估。该项目还为研究生的地震学和本科生培训提供了支持。俯冲带的高分辨率研究揭示了其结构和物理特性的复杂性和多样性。异质性倾向并沿着罢工影响板界面上的板耦合和滑动行为，以及在下板和上板上，最终在大范围的地震中最终达到高潮。法国和德国的资助机构支持hiper项目（PEDERNALES地震破裂区的高分辨率成像）。它在2016 MW 7.8 Pedernales破裂的北部厄瓜多尔俯冲带沿北部厄瓜多尔俯冲带沿北部厄瓜多尔俯冲带中获得了积极和被动的海地地震数据。 hiper项目包括60个海底地震仪和150个陆台，记录了3D网格的主动源镜头，然后是被动记录地震。在这里，美国团队通过部署3个组件短期节点（〜300）和60个宽带传感器的密集阵列来完成该项目。目的是显着使髋关节的陆上部分致密，以进行主动源记录。它还扩大了被动记录的光圈，以改善深度的横向覆盖范围和成像。组合的阵列为多尺度3D成像和检查结构，流体和滑移行为从地震到无性抗药性的变化之间的关系提供了非凡的机会。最终，它允许将地质，结构和地震性的地震学和地震学从地质和地震学调和观察结果。数据分析员工机器学习通用相位检测，以显着增加源检测。它还涉及旅行时间和环境噪声层析成像以及高频接收器的作用，是一系列多步骤倒置的投入，以限制地震遗传学区域沿线和上方的地震位置和地震结构。该奖项反映了NSF的法规任务，并以基础知识的优点和广泛的crietia crietia crietia crietia crietia crietia crietia crietia crietia crietia crietia crietia crietia crietia crietia crietia crietia cripitia均被视为珍贵。