CAREER: Using Upper Mantle Circulation Models to Evaluate the Role of the Asthenosphere: Tectosphere Contrast and Subduction Dynamics for Global Plate Tectonics

职业：利用上地幔环流模型评估软流圈的作用：全球板块构造的构造圈对比和俯冲动力学

• 批准号: 0643365
• 负责人: Thorsten Becker
• 金额: $ 51.13万
• 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: 2007
• 资助国家: 美国
• 起止时间: 2007-01-15 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0643365&HistoricalAwards=false
• 关键词: CAREER; Using; Upper; Mantle; Circulation

Using upper mantle circulation models to evaluate the role of the asthenosphere:tectosphere contrast and subduction dynamics for global plate tectonicsResearch focuses on global, numerical convection models with realistic plate boundaries, rheological and thermo-chemical contrasts, and improved constraints from seismology. The force partitioning in the mantle affects intraplate and plate boundary seismo-tectonics, and studying the mantle system by mechanical modeling holds the key to understanding plate motions and geologically recorded tectonic events. Efforts are divided into two research projects which are interrelated and have strong educational components. Project one uses circulation computations for an inversion of seismology data to evaluate the range of viscosity variations that are required by observables and laboratory results on the creep behavior of rocks (viscous tomography). Project two incorporates faulted margins into a global model (slabs, keels, and plates). Slabs drive and control the speed of the plates, and a more realistic inclusion of plate boundaries into global models is needed. It is evaluated to what degree slabs and trench motions vs. the tectosphere: asthenosphere contrast control global dynamics such as geopotential fields and seismic coupling. The unifying theme of research and educational efforts is the use of global flow models and structure derived from seismology and mineral physics. The goal is to arrive at a new kind of mantle circulation model that elucidates the roles of the asthenosphere in shaping plate tectonics and organizing deep Earth structure. The educational efforts in this project focus on course material for a new numerical methods class and two solid earth software modules for exploring mantle flow and tomography, both openly developed and freely shared. The goal is to allow learning through experimentation with modified research tools. Those tools are customizable so that they are useful for both general undergrad and graduate classes. Efforts strengthen the quantitative skills of students needed to tackle interconnected problems; useful for grad students to solve outstanding questions in mantle dynamics, and for non-specialists who need to make informed choices during planetary environmental challenges. Work contributes to a more transparent representation of disciplinary research results where traditional means of scientific communication are becoming unduly limiting. By providing both fundamental training in quantitative analysis and examples for novel seismological and geodynamical model sharing, the robustness of extra-disciplinary constraints are easier to evaluate. This is crucial if we are to accelerate progress on complex problems in plate tectonics and earth science in general.

使用上地幔环流模型评估软流圈的作用：全球板块构造的构造圈对比和俯冲动力学研究重点是具有真实板块边界、流变学和热化学对比的全球数值对流模型，以及来自地震学的改进约束。地幔内力的分配影响着板内和板内边界的地震构造，通过力学模拟研究地幔体系是理解板块运动和地质记录的构造事件的关键。工作分为两个研究项目，这两个项目相互关联，具有很强的教育成分。项目一利用循环计算对地震学数据进行反演，以评估可观测到的粘性变化范围和岩石蠕变行为的实验室结果(粘性层析成像)。项目二将断层边缘合并到一个全球模型中(平板、龙骨和板块)。板块驱动和控制板块的速度，需要更现实地将板块边界包含到全球模型中。对板块和海沟运动相对于构造圈的程度进行了评估：软流圈对比控制着全球动力学，如地球势场和地震耦合。研究和教育工作的统一主题是使用来自地震学和矿物物理学的全球流动模型和结构。其目标是得出一种新的地幔循环模型，阐明软流圈在塑造板块构造和组织地球深部结构方面的作用。这个项目的教育努力集中在一个新的数值方法课程的课程材料和两个用于探索地幔流动和层析的固体地球软件模块，这两个模块都是开放开发和免费共享的。其目标是通过使用改进的研究工具进行实验来进行学习。这些工具是可定制的，因此它们对普通本科生和研究生课程都很有用。这些努力加强了学生解决相互关联的问题所需的定量技能；有助于研究生解决地幔动力学中的悬而未决的问题，并有助于需要在地球环境挑战中做出明智选择的非专业人员。工作有助于更透明地展示学科研究成果，在这些领域，传统的科学交流手段正变得不适当地受到限制。通过提供定量分析的基础训练和新的地震学和地球动力学模型共享的例子，更容易评估跨学科约束的稳健性。如果我们要加快在板块构造和地球科学的复杂问题上的进展，这是至关重要的。