EAR-PF: Dynamics and melting of the upper mantle: Relating the length scales of compositional heterogeneity in the crust and mantle

托德·A·比安科博士获得了美国国家科学基金会地球科学博士后奖学金，将在布朗大学开展一项研究和教育计划。利用地幔动力学、岩石熔化和熔体运输的计算机模拟，该项目将测试不同尺寸分布的地幔不均匀如何影响地壳成分。此外，该项目将探讨熔体迁移的现实过程如何放大或削弱地壳组成中的地幔成分和地幔动力学的特征。计算机模拟将解决三维空间中的质量、动量和能量守恒问题，其性质可以捕捉上地幔的流变性、温度和密度变化。此外，模拟将包括不同大小的成分异质性的离散区域。计算机模拟的预测将与各种构造环境下的地壳成分观测进行比较，例如大洋中脊和异常厚的海底。地幔对流在很大程度上控制着地球的演化，因此对于理解对地球当前状态的观察是必不可少的一部分。地幔成分不均质性的大小和分布提供了地幔对流随时间变化的状态的图景。因此，通过量化观测到的地壳成分变化与推断的地幔变化之间的关系，该项目将在更广泛的意义上提高我们对地球如何演化的理解。此外，PI将为该项目的主办机构布朗大学提供本科生研究机会，并通过布朗大学由NSF资助的GK-12项目为当地教师提供研究经验。

Dr. Todd A. Bianco has been granted an NSF Earth Sciences Postdoctoral Fellowship to carry out a research and education plan at Brown University. Using computer simulations of mantle dynamics, rock melting and melt transport, this project will test how different size distributions in mantle heterogeneity affect crust composition. Further, the project will address how realistic processes of melt migration amplify or dampen the signature of mantle composition and mantle dynamics in crust composition. The computer simulations will solve conservation of mass, momentum, and energy in a three dimensional space with properties that capture the rheologic, temperature, and density variations in the upper mantle. In addition, the simulation will include discrete domains of compositional heterogeneity of varying sizes. Predictions from computational simulations will be compared to observations of crust composition at a variety of tectonic settings such as a mid-ocean ridge, and anomalously thick seafloor. Mantle convection controls much of the evolution of earth, and therefore is an essential piece to understanding observations of the current state of the earth. The size and distribution of compositional heterogeneity in the mantle gives a picture of the state of mantle convection over time. Therefore, by quantifying the relationship between observed compositional variation in the crust with inferred variation in the mantle, this project will, in a broader sense, improve our understanding of how the earth has evolved. In addition the PI will provide undergraduate research opportunities at Brown University, the host institution for the project, as well as research experience to local teachers through Brown University's NSF-funded GK-12 program.