Probing the mechanical properties of the crust and upper mantle using geodetic, remote sensing and seismological observations

利用大地测量、遥感和地震观测探测地壳和上地幔的力学特性

• 批准号: 2142152
• 负责人: Jean-Philippe Avouac
• 金额: $ 19.36万
• 依托单位: California Institute of Technology
• 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: 2021-12-15 至 2023-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2142152&HistoricalAwards=false
• 关键词: Probing; mechanical; properties; crust; upper

The Accomplishments Based Renewal will shed light on the laws that govern continental deformation and the seismic cycle, such as the processes of strain release during large earthquakes and the slow strain build up between successive earthquakes. This topic is of broad interest in geology and the result of the research could significantly advance methods for seismic hazard assessment. These are questions that the recent National Academies of Science, Engineering and Medicine report Earth in Time note as grand challenge questions in the Earth sciences. The researchers will analyze and model high precision GPS measurements of ground deformation before, during and after large earthquakes in California and Tibet using novel methods developed by the lead researcher. The project will support educational and outreach activities by the PI to train students and postdoctoral researcher involved in the project. The project will foster international scientific collaboration.The objective of this project is to advance the knowledge of crustal and upper mantle rheology and to improve the quantitative understanding of how seismicity relates to geodetic strain. The researchers will analyze High-Rate GNSS measurements of postseismic deformation and aseismic transients using a new methodology based on an Independent Component Analysis technique. They will compare the geodetic and seismicity observations with model predictions to constrain the friction properties governing the earthquake nucleation process and aseismic slip, and the viscosity structure. They will analyze data from California, related to the 2019, Mw7.1 Ridgecrest earthquake and the 2020 Westmorland swarm in particular, and data related to the Mw 7.4, 2021a Madoi earthquake in Tibet.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.

基于成就的更新将揭示控制大陆变形和地震周期的规律，例如大地震期间的应变释放过程和连续地震之间的缓慢应变积累。这一课题在地质学中具有广泛的意义，其研究结果将大大促进地震危险性评估方法的发展。这些问题是最近的美国国家科学院、工程院和医学院报告《地球在时间》中指出的地球科学中的重大挑战性问题。研究人员将使用首席研究员开发的新方法，分析和模拟加州和西藏大地震之前、期间和之后的高精度GPS地面变形测量。该项目将支持PI的教育和推广活动，以培训参与该项目的学生和博士后研究人员。该项目将促进国际科学合作，目的是增进对地壳和上地幔流变学的了解，并从数量上更好地了解地震活动与大地应变之间的关系。研究人员将使用基于独立分量分析技术的新方法来分析震后变形和抗震瞬态的高速GNSS测量。他们将比较大地测量和地震活动性观测与模型预测，以限制控制地震成核过程和地震滑动的摩擦特性以及粘性结构。他们将分析来自加州的数据，特别是与2019年7. 1级里奇克雷斯特地震和2020年威斯特摩兰震群有关的数据，以及与2021年西藏玛多7. 4级地震有关的数据。该奖项反映了NSF的法定使命，并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，被认为值得支持。

项目成果

Weak upper-mantle base revealed by postseismic deformation of a deep earthquake

• DOI: 10.1038/s41586-022-05689-8
• 发表时间: 2023-02
• 期刊: Nature
• 影响因子: 64.8
• 作者: Sunyoung Park;J. Avouac;Z. Zhan;A. Gualandi

The 2020 Westmorland, California Earthquake Swarm as Aftershocks of a Slow Slip Event Sustained by Fluid Flow

• DOI: 10.1029/2022jb024693
• 发表时间: 2022-11
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: K. Sirorattanakul;Z. Ross;M. Khoshmanesh;E. Cochran;M. Acosta;J. Avouac