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

地球？S表面覆盖着一层薄薄的(100公里)岩石板块的马赛克，称为岩石圈。虽然大陆下的岩石圈或多或少是永久性的，但海洋下的岩石圈是循环的吗？在深海海沟消费，在全球大洋中脊网络创造。一些大洋中脊的特点是地壳厚度、地震速度和玄武岩化学成分的不对称和平行变化，这些变化不能用仅仅由板块发散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动对海脊动力学的影响，或者是海脊几何形状的时间变化造成的。该项目将通过构建具有全球气流或演变的海脊几何形状的三维区域流动模型来检验东太平洋海隆和胡安德富卡海脊的这些假设。通过将地质、地球化学和地球物理参数的预测与在这些地点的观测进行比较，建立了这些模型。因此，这项研究将有助于了解地幔对山脊系统的控制和地球的一般地球动力学。除了向社区贡献新的软件外，该项目还将支持一名女性博士后研究员以及研究生和本科生参与。本科生的参与者将专门从马里兰大学附近的少数族裔社区招募。

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.