High-order accurate numerical models for magma migration beneath mid-ocean ridges: Geochemical consequences and geophysical implications

大洋中脊下岩浆迁移的高阶精确数值模型：地球化学后果和地球物理意义

• 批准号: 1156706
• 负责人: Yan Liang
• 金额: $ 40.95万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-15 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1156706&HistoricalAwards=false
• 关键词: order; accurate; numerical; models; magma

The generation of magmas in Earth's mantle and their segregation deep inside the Earth result in lavas that erupt from volcanoes on Earth's surface. How these processes take place and how they impart geochemical signatures in the resulting lavas is fundamental to our knowledge of how Earth behaves as a system. However, the processes that take place and complex interplay of geochemical and geophysicsl parameters that allow them to happen are presently inadequately understood. This research uses state-of-the-art numerical methods and computer algorithms and combines the expertise of both geosciences and applied mathematics to tackle the issues surrounding the physical and chemical proceses involved in partial melting of the mantle, melt migration, and melt-rock reaction in the generation of magma. From geochemical evidence gleaned from basaltic lavas erupted at mid-ocean ridge spreading centers, it is clear that the primary mechanism of melt transport requires the focusing of melt through channels in the mantle. However, the formation, distribution,and longieivy of these high-porosity channels is still a matter of speculation. To shed light on this problem, high order, adaptve, and parallel numerical models for simulating reactive magma migration in 2D and 3D settings directly relevant to melt migration below mid ocean ridges is being developed. The resulting simulation software will incorporate algorithms, approaches, and parameters that allow reactive dissolution of minerals, shear deformation, and decomperssional melting to be taken into account in models that calculate the distribution and segregation of melt. Additional considerations that link the geochemcial consequences and geophysical implications of melt migration will also be developed. The results will provide critical imput to general time-dependent melting models that allow geochemists to relate chemical heterogenaities observed in erupted basaltic lavas to their mantle sources. Broader impacts of the work include the funding of researchers at an institution in an EPSCoR state (Rhode island), building fundamental infrastructure for science via developing software that will be part of the Computational Infrastructure for Geodynamics software library which is publicly accessible, and training of undergraduates and graduate students in computational methods.

地球地幔中的岩浆产生及其在地球深处的隔离导致地球表面火山爆发的熔岩。 这些过程的发生方式以及它们如何在所产生的熔岩中传授地球化学特征是我们对地球行为作为系统的了解的基础。 然而，目前了解到的地球化学和地球物理参数的复杂相互作用，目前是不充分理解的。这项研究使用最先进的数值方法和计算机算法，并结合了地球科学和应用数学的专业知识，以解决麦芽岩一代中融化，融化迁移，融化迁移和融化岩石反应的围绕物理和化学计划的问题。从从玄武岩熔岩中收集的地球化学证据从中山山脊扩散中心爆发，很明显，熔体运输的主要机制需要通过地幔中的通道聚焦熔体。然而，这些高孔隙度通道的形成，分布和龙头仍然是猜测的问题。为了阐明这个问题，正在开发与中海脊以下熔体迁移直接相关的2D和3D设置中的反应性岩浆迁移的高级，适应和平行数值模型。所得的仿真软件将结合算法，方法和参数，以使矿物质，剪切变形和分解体融化的反应性溶解，以在计算熔体分布和分离的模型中考虑到。 还将开发将地球化学后果和地球物理迁移的地球物理含义联系起来的其他考虑因素。 结果将为一般时间依赖的熔融模型提供关键的含量，这些熔融模型使地球化学主义者能够将爆发的玄武岩熔岩中观察到的化学异生特征与其地幔源相关联。 这项工作的更广泛的影响包括通过开发软件建立科学基础设施的机构的研究人员的资金，该软件将成为可公开访问的地球动力学软件库的计算基础设施的一部分，以及对计算方法中的本科生和研究生的培训。