CAREER: Active forearc uplift, topographic growth, and permanent deformation above highly coupled subduction interfaces

事业：高度耦合的俯冲界面上方的活跃前弧隆起、地形生长和永久变形

• 批准号: 2046278
• 负责人: Kristin Morell
• 金额: $ 60万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2046278&HistoricalAwards=false
• 关键词: CAREER; Active; forearc; uplift; topographic

This program will provide key information about the physical properties and conditions that may control the size of earthquakes in subduction zones, regions which are known to host the largest earthquakes globally. This research will be integrated with a series of activities specifically designed to increase the number of successful geoscience and STEM students that identify as an underrepresented minority. This project will support undergraduate research internships for underrepresented minority students at the University of California, Santa Barbara and Santa Barbara City College, and will host workshops and local field trips specifically designed to increase geoscience awareness and broaden student participation in outdoor experiences. The project will also support the training and professional development of two PhD geoscience students, who will also act as mentors to the undergraduate students. Long-term forearc uplift and topographic growth above locked seismogenic zones can segment the megathrust along-strike, which is predicted to restrict the maximum size of large subduction zone earthquakes. However, the conditions and mechanisms that ultimately produce permanent vertical tectonism in these settings remain poorly constrained globally. The program will use a combination of field observations, numerical dating, low-temperature thermochronology and landscape evolution modeling to test between three primary mechanisms of rock uplift and topographic growth in the highly-coupled subduction zone regions of Nicoya Peninsula, Costa Rica, and Kodiak, Alaska, USA. Constraining these conceptual models will have important implications for processes that result in seismic segmentation, such as the physical and rheological conditions between the decollement, lower plate, and overriding plate, and how strain is partitioned between the megathrust and the upper plate.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.

该计划将提供有关可能控制俯冲带地震规模的物理特性和条件的关键信息，俯冲带是全球已知的最大地震发源地。这项研究将与专门设计的一系列活动相结合，以增加成功的地球科学和STEM学生的数量，这些学生认为自己是代表不足的少数群体。该项目将支持在加州大学圣巴巴拉分校和圣巴巴拉城市学院为未被充分代表的少数族裔学生提供本科生研究实习，并将举办专门为提高地球科学意识和扩大学生参与户外体验而设计的讲习班和当地实地考察。该项目还将支持两名地球科学博士生的培训和专业发展，他们也将担任本科生的导师。长期的弧前抬升和闭锁孕震带上方的地形生长可以分割沿走向的巨型逆冲断裂，预测这将限制大型俯冲带地震的最大规模。然而，在这些背景下最终产生永久垂直构造作用的条件和机制在全球范围内仍然受到很少的限制。该计划将结合现场观察、数值测年、低温热年代学和景观演化模型，测试哥斯达黎加尼科亚半岛和美国阿拉斯加科迪亚克等高度耦合的俯冲带地区岩石抬升和地形生长的三种主要机制之间的关系。约束这些概念模型将对导致地震分段的过程产生重要影响，例如滑脱、下板块和覆盖板块之间的物理和流变条件，以及如何在巨型逆冲和上板块之间分配应变。该奖项反映了NSF的法定使命，并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，被认为值得支持。