Collaborative Research: The 2020-2021 Alaska-Aleutian Earthquake Sequence: Cascading Events & Stress Loading of the Shallow Megathrust

合作研究：2020-2021 年阿拉斯加-阿留申地震序列：级联事件

• 批准号: 2152253
• 负责人: Julie Elliott
• 金额: $ 26.41万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2152253&HistoricalAwards=false
• 关键词: Collaborative; Research; 2020; 2021; Alaska

Estimating the size and location of future earthquakes remains an elusive goal in seismology and hazard research. This project studies the 2020 M7.8 Simeonof and 2021 M8.2 Chignik earthquakes that ruptured adjacent portions of the deeper interface between the North American and Pacific Plates offshore Alaska. The project will probe the relationship between these two earthquakes: how the Earth’s response to the 2020 Simeonof event may have affected the fault area that failed in the 2021 Chignik earthquake, the role of tectonics and geometry of this plate interface in earthquake occurrence, and how these events fit in the longer history of earthquakes along this plate boundary. Another key question is whether the yet unruptured shallower parts of the plate interface in this region may rupture in earthquakes that have the potential to create devastating, Pacific-wide tsunamis. This project will deploy four GPS/GNSS instruments around the Chignik earthquake rupture to better capture deformation following the earthquake. This project is a collaboration between the University of Alaska, Fairbanks and Michigan State University.This project will study crustal motions and stress changes due to the Simeonof and Chignik earthquakes directly and from readjustments of the Earth after the earthquakes. It will make use of multiple geophysical data sources, including high-precision GPS instrumentation, combined with modeling of crustal motions and stress changes. Careful separation of different tectonic processes, and models of realistic fault geometries informed by accurate earthquake relocation will yield improved models for how the plates moved during and after the Chignik earthquake. Coupled with similar, separately generated products for Simeonof earthquake and the earlier 1938 M8.3 earthquake in the same region, the project will create short- and long-term stress change models, and investigate how stress change may influence future rupture patterns. A virtual workshop will bring together subduction zone scientists, generate interest in the data produced through this project, showcase new findings, and inspire novel science and future opportunities.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.

估计未来地震的规模和位置仍然是地震学和危害研究的目标。该项目研究了2020 M7.8 Simeonof和2021 M8.2 Chignik地震，这些地震破裂了北美和太平洋板块阿拉斯加近海之间较深界面的相邻部分。该项目将探究这两次地震之间的关系：地球对2020年Simeonof事件的反应可能影响了在2021年Chignik地震中失败的断层区域，地震发生中该板界面的作用和该板界面的几何形状的作用，以及这些事件在该板块边界的较长的地震历史中如何适合这些事件。另一个关键的问题是，该区域中未破坏的板界面的较浅部分是否可能破裂，这些地震有可能产生毁灭性的，太平洋范围内的海啸。该项目将在Chignik Earth地震破裂周围部署四种GPS/GNSS仪器，以更好地捕获地震后的变形。该项目是阿拉斯加大学，费尔班克斯大学和密歇根州立大学之间的合作。该项目将研究地壳动作和压力变化，这是由于Simeonof和Chignik Earth Quakes直接，直接从地球地震后的地球重新调整中。它将利用多种地球物理数据源，包括高精度GPS仪器，并结合地壳运动和应力变化的建模。仔细分离不同的构造过程，以及通过准确地震搬迁告知的现实断层几何模型将产生改进的模型，以在板块期间和之后的板块如何移动。再加上与Simeonof地震的类似，单独生成的产品以及1938年M8.3早期的同一地区地震，该项目将创建短期和长期的应力变化模型，并研究压力变化如何影响未来的破裂模式。虚拟研讨会将汇聚俯冲区科学家，对通过该项目产生的数据产生兴趣，展示新的发现，并启发了新颖的科学和未来机会。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准通过评估来评估的。