CAREER: Path Dependent Slip of the Shallow Subduction Megathrust

该项目是一项综合研究和教育计划，旨在研究在美国太平洋西北部等构造环境中产生地震和海啸的过程。“俯冲带”是板块的边界，其中一个板块俯冲到另一个板块之下。它们是地球上最大的地震和海啸的发源地。这两种危害都受边界沿着岩石的力学性质控制。这些性质因寄主岩石矿物学的不同而在区域上有所不同。当岩石被拖入俯冲带时，它们也会经历不同的物理和化学变化。 这些变化也会影响其机械性能。在这里，研究小组研究了不同物理和化学路径对俯冲带岩石力学性质的影响。 他们对在目标板块边界收集的岩石标本进行变形实验。 研究结果有助于揭示断层产生大规模逆冲断层地震的行为。 它们还有助于更好地评估区域灾害。该项目包括为一名职业生涯初期的女科学家提供支助。此外，它促进了一个由三部分组成的教育计划，以培养学生在岩石力学在所有级别，从K-12，本科和研究生水平。该奖项为期5年，由NSF地球物理学、构造学和海洋地质学地球物理学项目共同资助。最浅的俯冲巨型逆冲断层承载着各种各样的滑动模式，包括海啸地震。浅层条件下的断层滑动模式被认为是由板块边界沿着沉积物和岩石的物理性质以及孔隙流体压力和温度等外部条件所控制的。然而，没有一个综合的模型，岩性控制滑动行为。 外部变量如何控制这些岩性的变形也不清楚。在这里，该团队通过实验研究了浅俯冲带岩石的路径相关强度和变形行为。 该项目有一个基于实地的组成部分，以收集具有相关矿物学和微观结构的自然变形标本。研究和教育计划的目标是：⑴确定俯冲沉积物和玄武岩经历的矿物学和孔隙度的变化如何促进或抑制不同的滑动模式; ⑵量化导致孔隙流体压力升高的路径如何影响不同的滑动模式;（3）推出一个由三部分组成的教育计划，包括建立一个移动的教学实验室，一个以探究为基础的电子课程，该奖项反映了NSF的法定使命，并被认为是值得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的支持。

This project is an integrated research and education plan to study the processes generating earthquakes and tsunamis in tectonic environments like the Pacific Northwest of the United States. "Subduction zones" are tectonic plate boundaries where one plate dives beneath another. They host Earth’s largest earthquakes and tsunamis. Both hazards are controlled by the mechanical properties of the rocks present along the boundary. These properties vary regionally due to different mineralogy in the host rocks. Rocks also undergo different physical and chemical changes as they are dragged into a subduction zone. These changes affect their mechanical properties as well. Here, the team study the effects of different physical and chemical paths on the mechanical properties of subduction-zone rocks. They carry out deformation experiments on rock specimens collected in targeted plate boundaries. Results helps unveiling the behavior of faults generating megathrust earthquakes. They also allow better assessing regional hazards. This project includes support for an early-career female scientist. In addition, it promotes a 3-part education plan to train students in rock mechanics at all levels, from K-12, to undergraduate and graduate levels. The 5-year award is co-funded by NSF Geophysics, Tectonics, and Marine Geology & Geophysics programs. The shallowest extent of subduction megathrusts hosts a variety of slip modes, including tsunamigenic earthquakes. The mode of fault slip at shallow conditions is proposed to be controlled by the physical properties of the sediments and rocks along the plate boundary, as well as external conditions like pore fluid pressure and temperature. However, there is no comprehensive model for which lithologies control slip behavior. How extrinsic variables control the deformation of these lithologies is also unclear. Here, the team studies experimentally the path-dependent strength and deformation behavior of shallow subduction-zone rocks. The project has a field-based component to collect naturally deformed specimens with relevant mineralogy and microstructures. The goals of the research and education plan are: (1) to determine how changes in mineralogy and porosity, experienced by subducted sediments and basalt, promote or inhibit different slip modes; (2) to quantify how the paths that lead to elevated pore fluid pressures affect different modes of slip; (3) to launch a 3-part education plan that includes the development of a mobile teaching laboratory, that of an inquiry-based electronics course, and the integration of undergraduate students in research and teaching activities.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.