ABR: Mantle Circulation Models: Development and Application to Geophysical and Geochemical Observables

ABR：地幔环流模型：地球物理和地球化学可观测值的开发和应用

• 批准号: 0440017
• 负责人: Richard O'Connell
• 金额: $ 39.65万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-12-15 至 2009-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0440017&HistoricalAwards=false
• 关键词: ABR; Mantle; Circulation; Models; Development

The proposed work will develop and use models of mantle flow and convection to understand the state and evolution of the solid earth. The work will include studies of mantle plumes and hotspots; plumes provide an indicator of mantle flow throughout the depth of the mantle, and recent seismic observations of plumes will allow a direct comparison of models of mantle flow with observation of plumes that are moved and distorted by mantle flow. These results will also be important for understanding hotspot tracks and plate motions, as well as flow in the mantle. The work will also address the motions of subducted material and other heterogeneities in the mantle, and will relate them to geochemical signatures of heterogeneity in the mantle. This will build upon recently developed statistical models of the development and evolution of mantle heterogeneity, and will provide a means of relating observed geochemical evidence of heterogeneity with dynamical processes in the mantle. Further development of flow and convection models will be done to deal more realistically with thermal convection and mantle rheology. Recent developments for inversion of models will be applied in order to better constrain our conclusions. Since the models predict a range of geophysical phenomena (including the geoid, plate motions, polar wander) the results of the model studies will be systematically applied to these other phenomena.The work will relate the dynamic processes of flow and convection to the emerging seismological pictures of mantle structure, as well as to the geochemical evolution of the Earth. This will allow a more unified view of the workings of the Earth's interior on both short and long time scales. The work will involve the training of graduate students, and will also develop numerical models that will be available to other researchers. The results of the work will have broad implications for understanding the dynamics and evolution of the Earth, and will relate dynamical, tectonic and geochemical views of the evolution and working of the Earth system, which represents an extremely active area of earth science research.

拟议的工作将开发和使用地幔流动和对流的模型，以了解固体地球的状态和演变。这项工作将包括研究地幔柱和热点;地幔柱提供了整个地幔深度的地幔流的指标，最近对地幔柱的地震观测将使人们能够直接比较地幔流模型和对被地幔流移动和扭曲的地幔柱的观测。这些结果对于理解热点轨迹和板块运动以及地幔流动也很重要。这项工作还将解决俯冲物质和地幔中其他不均匀性的运动，并将它们与地幔中不均匀性的地球化学特征联系起来。这将建立在最近开发的地幔不均匀性的发展和演变的统计模型，并将提供一种手段，在地幔中的动力学过程与所观察到的地球化学证据的不均匀性。流动和对流模型的进一步发展将更现实地处理热对流和地幔流变学。 为了更好地约束我们的结论，将应用模型反演的最新发展。由于模型预测了一系列地球物理现象（包括大地水准面、板块运动、极移），因此模型研究的结果将系统地应用于这些其他现象，这项工作将把流动和对流的动态过程与地幔结构的地震学图像以及地球的地球化学演化联系起来。这将使人们对地球内部在短期和长期尺度上的运作有一个更统一的看法。这项工作将涉及研究生的培训，还将开发可供其他研究人员使用的数值模型。这项工作的结果将对了解地球的动力学和演变产生广泛的影响，并将从动力学、构造学和地球化学的角度来看待地球系统的演变和运作，地球系统是地球科学研究的一个极为活跃的领域。