CAREER: Slab structure and dynamics of arcuate shaped subduction zones

职业：弓形俯冲带的板片结构和动力学

• 批准号: 1054638
• 负责人: Meghan Miller
• 金额: $ 52.74万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-10-01 至 2018-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1054638&HistoricalAwards=false
• 关键词: CAREER; Slab; structure; dynamics; arcuate

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.

板块构造的有趣特征之一是，许多活跃和古老的俯冲带具有明显的弧形形态，其地形表达式延伸了数百到数千公里。 一般而言，研究俯冲对于理解地球的演变至关重要。 更充分地了解岩石圈的结构和动力学，地球相对刚性外壳，沿高度弧形板块边界的俯冲将有助于限制地质记录的构造事件，全局板块运动，板界边界变形，以及俯冲的海洋岩石圈在海洋岩石圈中的作用地幔对流。 该职业奖的总体研究目标是通过对四个主动弧的研究进行了对弧形形状融合边缘的结构和形态演变的发展：玛丽安娜，安提斯，betic-rif和banda arcs，使用一系列范围工具，包括地震成像和地球动力学建模。 预期的发现将为板块构造的基础研究提供重要贡献，对构造板界边界的结构和演变的理解以及这些地区的地震性的性质得到了改善。 教育目标是作为下一代地球科学家培训和准备本科生的研究生，他们能够理解并有效利用俯冲区的地球物理和地质数据。这一职业奖将详细研究，详细研究深层的起源和进化四个目标弧的地球结构。 例如，这些弧的改进成像和建模将提供一种测试地球动力学假设的方法，例如，由于冷，密集的岩石圈的相互作用，弯曲的俯冲区已演变为当前的构型，具有积极的浮力，例如海洋大陆岩石层岩石裂层。 ，导致弯曲的形态由于沟槽回滚和平板碎片。 四个弧系统中的每个系统都具有不同的长度尺度和地形表达式，独特的单个构造历史和板构型，但它们都表现出高度弧形的收敛边界结构，并且在其尖端的浮体壳和岩石圈体中受到界定。 该项目建议检查这些相似性和差异，以便更好地了解在滚回，地幔流以及弧线末端的浮力“固定”特征的影响方面，紧密弯曲的收敛边界处的地球动力进化和地幔结构。 该奖项还将基于对地震性，火山主义，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现场成分将包括沿着安提尔斯群岛和摩洛哥北部的宽带地震数据的部署和收集，以及区域地质映射以及沿活动弧的部分进行采样。 本科生和研究生都将参加该课程以及通过该奖项开发的其他教学模块，并将成为USC问题的一部分，而没有护照计划，该计划将基于询问的学习练习与外国的研究结合在一起。