Collaborative Research: RAPID: Response to the 29 July 2021 Chignik M8.2 Earthquake

合作研究：RAPID：对 2021 年 7 月 29 日奇格尼克 M8.2 地震的响应

• 批准号: 2147422
• 负责人: Jeffrey Freymueller
• 金额: $ 7.24万
• 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: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2147422&HistoricalAwards=false
• 关键词: Collaborative; Research; RAPID; Response; 29

This RAPID award is a response to The July 2021 Chignik earthquake (M8.2) along the Alaskan Peninsula. This is the biggest earthquake in the US since 1965 (Rat Islands). It ruptured a segment of the megathrust offshore of the Alaska Peninsula, which last ruptured in 1938. The project deploys an integrated on-land observational field campaigns: geodesy to rapidly resurvey nearby monuments and document earthquake-related deformation, and seismology to deploy nearby instruments to record aftershocks. Understanding this earthquake will provide critical information for evaluating models of earthquake behavior and hence hazard among the planet’s largest earthquakes. Although only a small tsunami occurred, understanding better the rupture will allow for more realistic tsunami hazard assessments. The earthquake also provides ample opportunities for broadening participation in science, through rapidly making available data to the seismic and geodetic research communities. The project includes outreach to local schools, communities and governments and restarts a popular blog focused on geophysics in Alaska.The Chignik earthquake is a very rare example of a fault segment with two great earthquakes in the instrumental record, and is a critical locale to test theories of how seismic cycles work. The earthquake follows a pattern of along-strike segmentation previously documented between segments with large differences in locking behaviors and earthquake histories. The cause of this segmentation (or indeed of the variation in slip behavior more generally) remains uncertain, and collecting new data may elucidate the controlling mechanisms behind interseismic and coseismic rupture segmentation. Additionally, the earthquake provides an excellent laboratory to test theories of fault loading between segments and of our understanding of postseismic deformation. Almost precisely a year earlier, a M7.8 ruptured the abutting Shumagin segment to the west, indicating some possibility of triggering. That relationship can be explored, as well as the potential for bringing the next segment to the east closer to failure. The project takes advantage of decades of geodetic work on the Shumagins, Alaska Peninsula, and nearby islands, and the large 2018-9 GeoPRISMS-EarthScope-supported Alaska Amphibious Community Seismic Experiment. The project's outcome will be valuable in addressing questions related to the characteristics of earthquakes as articulated in the Earth in Time report from the National Academies of Science, Engineering and Medicine.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 RAPID 奖项是对 2021 年 7 月阿拉斯加半岛发生的奇格尼克地震 (M8.2) 的回应，这是美国自 1965 年以来最大的地震（拉特群岛），它导致阿拉斯加半岛近海的一段巨型逆冲断层破裂。最后一次破裂是在 1938 年。该项目部署了综合陆地观测现场活动：大地测量，以快速重新勘察附近的纪念碑并记录与地震相关的变形，以及地震学部署附近的仪器来记录余震将为评估地震行为模型以及地球上最大地震的危害提供关键信息。通过向地震和大地测量研究界快速提供数据，地震还为扩大科学参与提供了充足的机会。该项目包括向当地学校、社区和政府进行推广，并重新启动了一个专注于科学的流行博客。阿拉斯加的地球物理学。奇格尼克地震是仪器记录中发生过两次大地震的断层段的一个非常罕见的例子，也是检验地震周期如何运作的理论的关键地点。地震遵循先前的沿走向分割模式。这种分段的原因（或者更普遍的滑动行为的变化）仍然不确定，收集新数据可以阐明震间和同震背后的控制机制。此外，这次地震提供了一个很好的实验室来测试断层荷载理论以及我们对震后变形的理解。几乎就在一年前，M7.8 地震使西边毗邻的舒马金断层发生了破裂，这表明存在一定的破裂可能性。可以探索这种关系，以及使东部的下一部分更接近失败的潜力。该项目利用了舒马金斯、阿拉斯加半岛和附近岛屿以及大型岛屿数十年的大地测量工作。 2018 年 9 月 GeoPRISMS-EarthScope 支持的阿拉斯加两栖社区地震实验该项目的成果对于解决与美国国家科学、工程和医学院的《地球实时报告》中阐述的地震特征相关的问题非常有价值。该奖项。通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。