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

Todd a . Bianco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。利用计算机模拟地幔动力学、岩石熔融和熔体运输，该项目将测试不同大小的地幔非均质分布如何影响地壳组成。此外，该项目将解决熔融迁移的现实过程如何放大或抑制地壳组成中的地幔组成和地幔动力学特征。计算机模拟将在三维空间中解决质量、动量和能量守恒问题，并具有捕捉上地幔流变、温度和密度变化的特性。此外，模拟将包括不同大小的组成异质性的离散域。计算模拟的预测结果将与各种构造环境下的地壳组成观测结果进行比较，例如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，因此是理解地球当前状态观测的重要组成部分。地幔成分非均质性的大小和分布反映了地幔对流随时间变化的状态。因此，通过量化地壳中观测到的成分变化与推断出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进化的理解。此外，该项目还将在布朗大学（该项目的主办机构）提供本科生研究机会，并通过布朗大学的nsf资助的GK-12项目向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.