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

该项目将提供有关俯冲带地震的物理性质和条件的关键信息，这些物理性质和条件可能会控制俯冲带地震的大小，这些地区被认为是全球最大地震的举办地。这项研究将与一系列专门设计的活动相结合，以增加成功的地球科学和STEM学生的数量，这些学生被视为代表性不足的少数群体。该项目将支持加州大学圣巴巴拉分校和圣巴巴拉城市学院少数族裔学生的本科生研究实习，并将举办专门旨在提高地球科学意识和扩大学生户外体验参与的研讨会和当地实地考察。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。长期的前弧隆升和闭锁发震带上的地形生长使大逆冲构造沿走向分段，这将限制大俯冲带地震的最大规模。然而，在这些环境中最终产生永久垂直构造的条件和机制在全球范围内仍然缺乏约束。该项目将结合现场观测、数值测年、低温热年代学和景观演化模型，在哥斯达黎加尼科亚半岛和美国阿拉斯加科迪亚克高度耦合的俯冲带地区测试岩石隆起和地形生长的三种主要机制。限制这些概念模型将对导致地震分割的过程具有重要意义，例如滑脱、下板块和上覆板块之间的物理和流变条件，以及大逆冲构造和上板块之间的应变如何分割。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.