CAREER: Slab structure and dynamics of arcuate shaped subduction zones

板块构造的一个有趣特征是，许多活动和古老的俯冲带具有明显的弧形地貌，其地形表达长达数百至数千公里。总的来说，研究俯冲对于理解地球的演化是至关重要的。更充分地了解岩石圈的结构和动力学，岩石圈是地球相对刚性的外壳，沿高度弧形的板块边界俯冲，将有助于约束地质记录的构造事件、全球板块运动、板块边界变形以及俯冲的大洋岩石圈在地幔对流中的作用。该职业奖的主要研究目标是通过使用一系列工具，包括地震成像和地球动力学建模，通过研究四个活动弧段：马里亚纳弧、安的列斯弧段、Btic-Rif弧段和班达弧段，更好地了解弧形收敛边缘的结构和形态演变。这些预期的发现将为板块构造的基础研究、更好地了解构造板块边界的结构和演化以及这些地区地震活动的性质提供重要贡献。教育目标是培养和培养本科研究生，使他们成为能够理解和有效利用俯冲带地球物理和地质数据的下一代地球科学家。这个职业奖将详细研究四个目标弧区地球深部结构的起源和演化。改进对这些弧线的成像和建模将提供一种检验地球动力学假说的方式，例如，弯曲俯冲带已经演变成目前的形态，这是由于寒冷、致密的海洋岩石圈与正浮力特征，如大洋高原或大陆岩石圈的相互作用，导致海沟回滚和板块碎裂导致弯曲的形态。这四个弧系中的每一个都有不同的长度尺度和地形表达，独特的个别构造历史和板块构造，但它们都表现出高度弧形的会聚边界结构，并在其尖端被浮力地壳和岩石圈实体所包围。该项目建议研究这些相似和不同之处，以更好地了解地球动力学演化和紧密弯曲会聚边界上的地幔结构，包括回滚、地幔流动和弧端浮力“钉扎”特征的影响。该奖项还将资助基于实地和课堂学习对地震活动、火山活动、地幔对流、板块构造和地质过程的理解的综合教育和研究计划的发展。新的构造物理学课程的实地部分将包括沿安的列斯群岛和摩洛哥北部的几个区域部署和收集宽带地震数据，以及沿部分活动弧线进行区域地质测绘和取样。本科生和研究生都将参加通过该奖项开发的课程和其他教学模块，并将成为南加州大学无护照问题计划的一部分，该计划将探究性学习练习与在外国的研究相结合。

One of the intriguing features of plate tectonics is that many active and ancient subduction zones have a pronounced arc-shaped morphology, with their topographic expressions stretching over hundreds to thousands of kilometers in length. Studying subduction, in general, is essential to understanding the evolution of the planet. More fully understanding the structure and dynamics of lithosphere, the relatively rigid outer shell of the Earth, subducting along highly arcuate plate boundaries will aid in constraining geologically recorded tectonic events, global plate motions, plate boundary deformation, and the role of subducted oceanic lithosphere in mantle convection. The overarching research goal of this CAREER award is development of an improved understanding of the structural and morphological evolution of arcuate shaped convergent margins through the study of four active arcs: the Mariana, Antilles, Betic-Rif, and Banda arcs, using a range of tools, including seismological imaging and geodynamic modeling. The expected findings will provide an important contribution to basic research on plate tectonics, an improved understanding of the structure and evolution of the tectonic plate boundaries, and the nature of seismicity in these regions. The educational goal is to train and prepare undergraduate graduate students as the next generation of geoscientists who are able to understand and effectively utilize both geophysical and geological data from subduction zones.This CAREER award will investigate, in detail, the origin and evolution of the deep Earth structure of four target arcs. Improved imaging and modeling of these arcs will provide a way to test geodynamic hypotheses, for example, that curved subduction zones have evolved into their current configuration due to interactions of cold, dense oceanic lithosphere with positively buoyant features, such as oceanic plateaus or continental lithosphere, resulting in curved morphology as a result of trench rollback and slab fragmentation. Each of the four arc systems, have different length scales and topographic expressions, unique individual tectonic histories and plate configurations, yet they all exhibit highly arcuate convergent boundary structures and are bounded by buoyant crustal and lithospheric bodies at their cusps. This project proposes to examine these similarities and differences in order to better understand the geodynamic evolution and mantle structure at tightly curved convergent boundaries in terms of rollback, mantle flow, and the influence of buoyant "pinning" features at the ends of the arcs. This award will also fund development of an integrated education and research program based on understanding of seismicity, volcanism, mantle convection, plate tectonics, and geologic processes from both field and classroom based learning. The field component of the new Tectonophysics course will include deployment and collection of broadband seismic data along the several of the Antilles Islands and in northern Morocco, plus regional geologic mapping and sampling along portions of the active arcs. Both undergraduates and graduate students will participate in the course and other teaching modules developed through this award and will be part of USC's Problems Without Passports program that combine inquiry-based learning exercises with research in a foreign country.