Collaborative Proposal: Influence of plate boundary evolution and global mantle flow on ridge geodynamics

地球?地球表面覆盖着一层被称为岩石圈的薄（100公里）岩石板块。虽然大陆下面的岩石圈或多或少是永久的，但海洋下面的岩石圈是循环的？在深海海沟中消耗，在大洋中脊的全球网络中产生。一些洋中脊在地壳厚度、地震速度和玄武岩化学方面具有不对称和脊平行的变化，而不能仅仅用板块分裂引起的被动扩张来解释。相反，最近的研究表明，这种复杂性可能反映了大规模地幔流对海脊动力学的影响，或者是海脊几何形状随时间变化的结果。该项目将通过构建三维区域流动模型来测试东太平洋隆起和胡安·德·富卡海岭的这些假设，该模型包含强加的全球流动或不断演变的海岭几何形状。通过将地质、地球化学和地球物理参数的预测与这些地点的观测结果进行比较，建立模型。因此，这项研究将有助于理解地幔对脊系统的控制和地球的一般地球动力学。除了为社区贡献新软件外，该项目还将支持女性博士后研究员以及研究生和本科生的参与。本科生参与者将特别从马里兰大学附近的少数民族社区招募。

Earth?s surface is covered by a, mosaic of thin (100km) rocky plates known as the lithosphere. While the lithosphere beneath the continents is more-or-less permanent, the lithosphere beneath the oceans is recycled ? consumed at deep sea trenches and created at a global network of mid-ocean ridges. Several mid-ocean ridges feature asymmetric and ridge-parallel variations of crustal thickness, seismic velocity, and basalt chemistry than cannot be explained by passive spreading caused by plate divergence only. Instead, recent studies suggest that this complexity may reflect an influence of large-scale mantle flow on ridge dynamics, or result from temporal changes in ridge geometry. This project will test these hypotheses for the East Pacific Rise and the Juan de Fuca Ridge by constructing three-dimensional regional flow models with imposed global flow or evolving ridge geometries. The models by comparing predictions of geological, geochemical, and geophysical parameters against observations at these sites. This study will thus contribute to understanding mantle controls on the ridge system and the general geodynamics of the Earth. In addition to contributing new software to the community, this project will support participation by a female post-doctoral fellow and both graduate and undergraduate students. Undergraduate participants wil be specifically recruited from the minority community in the vicinity of the University of Maryland.