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灾害研究中难以实现的目标。该项目研究了 2020 年 M7.8 西蒙诺夫地震和 2021 年 M8.2 奇格尼克地震，这些地震导致北美板块和太平洋板块近海深层界面的相邻部分破裂。该项目将探讨这两次地震之间的关系：地球对 2020 年西蒙诺夫地震的反应可能如何影响了这次地震中发生的断层区域。 2021 年奇格尼克地震，该板块界面的构造和几何形状在地震发生中的作用，以及这些事件如何适应沿该板块边界的地震的较长历史另一个关键问题是板块界面尚未破裂的较浅部分是否在该地震中。该地区可能会在地震中破裂，从而有可能引发毁灭性的全太平洋海啸。该项目将在奇格尼克地震破裂周围部署四个 GPS/GNSS 仪器，以更好地捕获地震后的变形。是阿拉斯加大学、费尔班克斯分校和密歇根州立大学之间的合作项目。该项目将直接研究西蒙诺夫地震和奇格尼克地震造成的地壳运动和应力变化，以及地震后地球的重新调整，它将利用多种地球物理数据。包括高精度 GPS 仪器在内的数据源，结合地壳运动和应力变化的建模，以及通过准确的地震重定位获得的真实断层几何模型的仔细分离，将产生改进的模型。结合奇格尼克地震期间和之后板块移动的类似西蒙诺夫地震和同一地区早期 1938 年 M8.3 地震的类似产品，该项目将创建短期和长期应力变化模型，并研究应力如何变化。虚拟研讨会将汇集俯冲带科学家，激发人们对通过该项目产生的数据的兴趣，展示新的发现，并激发新的科学和未来的机会。该奖项是 NSF 的法定使命，并被认为是值得的。通过使用基金会的智力优势和更广泛的影响审查标准进行评估来提供支持。