Collaborative Research: Heterogeneities of the Alaska Megathrust: From the Overriding Plate to the Subducting Slab

合作研究：阿拉斯加巨型逆冲断层的异质性：从上覆板块到俯冲板片

• 批准号: 2330939
• 负责人: Songqiao Wei
• 金额: $ 34.72万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-15 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2330939&HistoricalAwards=false
• 关键词: Collaborative; Research; Heterogeneities; Alaska; Megathrust

Subduction, where one tectonic plate moves beneath another, can lead to large magnitude earthquakes. The Alaska Peninsula has a history of such events, making it an ideal location to explore the relationship between different geological features and these earthquakes. This project will use high-quality data from community seismic experiments to better understand the structure of the Earth's plates in this region. This will in turn allow testing hypotheses related to how structures in the overriding plate may influence earthquake processes. This research not only benefits Alaska but contributes to a global understanding of earthquake processes, ultimately helping to better prepare for and mitigate earthquake hazards at subduction zones. The broader impacts include training opportunities for graduate and undergraduate students at minority-serving institutions and support for a postdoctoral scholar.The proposed project focuses on seismic imaging of the Alaska-Aleutian subduction zone, specifically the Alaska Peninsula, to investigate the relationships between the structure of the subduction zone and megathrust earthquake properties. The study aims to enhance the understanding of factors influencing megathrust earthquakes. Utilizing data from the Alaska Amphibious Community Seismic Experiment, EarthScope Transportable Array, and USGS Alaska Earthquake Center, the research will jointly employ scattered wave and body wave tomography to obtain high-resolution constraints on the structure of the plate interface, overriding and subducting plates. The overarching goal is to test hypotheses regarding the roles of pre-existing structures in the overriding crust in megathrust earthquake processes. The canonical view of the seismogenic megathrust as a planar fault with variably locked asperities remains a useful framework, but questions persist about the specific roles of these features in seismogenesis. The research will address these uncertainties by analyzing the depth and seismic structure of the plate interface, as well as variations along dip and strike directions. Additionally, the seismic structures of the overriding and subducting plates will be examined to determine their roles in slip behaviors. By integrating scattered waves and body-wave tomography, the project aims to identify correlations between different structural features and interseismic/coseismic slips. The ultimate goal is to enhance the fundamental understanding of how geological structures influence seismic behavior, not only in Alaska but also in subduction zones worldwide, aligning with community initiatives such as Subduction Zones in 4-Dimensions (SZ4D). This project is jointly funded by the Marine Geology and Geophysics program in the Division of Ocean Sciences, the Established Program to Stimulate Competitive Research (EPSCoR), and the Geophysics program in the Division of Earth Sciences.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.

一个构造板在另一个构造板移动下移动的俯冲会导致大范围地震。阿拉斯加半岛有此类事件的历史，使其成为探索不同地质特征与这些地震之间关系的理想场所。该项目将使用社区地震实验的高质量数据，以更好地了解该地区地球板的结构。这反过来允许测试与覆盖板中的结构如何影响地震过程有关的假设。这项研究不仅使阿拉斯加受益，而且有助于全球对地震过程的理解，最终有助于更好地为俯冲区的地震危害做好准备和减轻地震危害。更广泛的影响包括为少数族裔服务机构的研究生和本科生的培训机会以及对博士后学者的支持。拟议的项目着重于阿拉斯加 - 阿拉斯加亚利特俯冲区的地震成像，特别是阿拉斯加半岛，以调查俯冲区域和Megathrust地震属性的结构之间的关系。该研究旨在增强对影响大地震的因素的理解。利用来自阿拉斯加两栖群落地震实验的数据，可运输的Earthscope可运输阵列和阿拉斯加地震中心，该研究将共同​​采用散落的波浪和人体波断层扫描，以获得对板界面，超压和俯冲平板结构的高分辨率约束。总体目标是检验有关先前存在的结构在大型地震过程中覆盖壳中的作用的假设。地震生成的巨大的典范视图作为平面断层，其锁定的悬垂性多样性仍然是一个有用的框架，但是关于这些特征在地震生成中的特定作用的问题仍然存在。该研究将通过分析板界面的深度和地震结构以及沿倾角和罢工方向的变化来解决这些不确定性。此外，将检查覆盖板和俯冲板的地震结构，以确定其在滑动行为中的作用。通过整合散射的波浪和人体波断层扫描，该项目旨在确定不同结构特征与经济震动/coseissic滑动之间的相关性。最终目标是增强对地质结构如何影响地震行为的基本理解，不仅在阿拉斯加，而且在全球俯冲区域，与社区倡议（如俯冲区（如四维）（SZ4D））保持一致。该项目由海洋科学部的海洋地质与地球物理计划共同资助，启发竞争研究的既定计划（EPSCOR）和地球科学部的地球物理学计划。该奖项反映了NSF的法规任务，并认为通过基金会的知识优点和广泛的crietia crietia criter criter criter criter criteria crietia criter criteria criteria criteria criteria crietia criteria criteria均值得一提。