Collaborative Research: Using plate circuits to constrain motion between East and West Antarctica

这项提案将解决东南极和西南极之间的动议。对晚白垩世和新生代运动的估计来自于将连接南极洲东部和澳大利亚的板块环路相加，再到豪勋爵上升到太平洋板块到南极洲西部。然而，该地区板块运动的历史仍然存在重大不确定性，导致对全球板块电路的影响截然不同，没有明确表明哪种模型是正确的。PIS建议将这一运动分为两部分：42 Ma以来的运动和42 Ma之前的运动。对于较年轻的时间间隔，PI将通过利用不寻常的板块几何结构来提高旋转精度，使它们能够求解五边界、四板块配置。对于较老的时间间隔，计算东南极和西南极之间的运动的唯一方法是通过漫长的Aus-Pac板块电路。这个时间间隔中的困难在于，对于Aus-East Ant边界，有三组结果截然不同的旋转。在50 Ma之前，澳大利亚和蚂蚁之间对基本运动的分歧导致了在罗斯海西部和埃尔斯沃斯陆地附近预测的运动的巨大差异。PIS建议重新审查Aus-Pac板电路中的关键元素，目的是减少不确定性，尽可能使用定量方法，并解决涉及替代解释的一些关键问题。更广泛的影响：这项工作的科学影响是改进了对南极板块构造历史的理解，将其纳入全球模型。该项目将为每个机构的一名研究生提供支持。该项目的结果将在全球板块运动和板块重建数据库中公布。此外，成绩将用于中学小组的外展工作。坎德制作了一部围绕Aus-Pac板块电路的板块运动的动画电影，他将其用作本科生和研究生教学的一部分。他计划使用这个项目的成果来更新和扩展这个动画。

This proposal will address the motion between East and West Antarctica. The estimates of motion in the Late Cretaceous and Cenozoic come from summing the plate circuit linking East Antarctica to Australia to the Lord Howe Rise to the Pacific plate to West Antarctica. However, major uncertainties remain in the history of the plate motions in this region, leading to widely different implications for the global plate circuit, without a clear indication of which model is correct. The PIs propose to analyze this motion in two parts: motion since 42 Ma and motion before 42 Ma. For the younger time interval, the PIs will improve accuracy of rotations by taking advantage of an unusual plate geometry that enables them to solve a five-boundary, four-plate configuration. For the older time interval, the only way to calculate motion between East and West Antarctica is via the long Aus-Pac plate circuit. The difficulty in this time interval is that there are three sets of rotations with distinctly different results for the Aus-East Ant boundary. The disagreement over the fundamental motion between Aus and Ant before 50 Ma leads to large differences in the predicted motion in the Western Ross Sea and near Ellsworth Land. The PIs propose to re-examine the key elements in the Aus-Pac plate circuit with the objective of reducing uncertainties, using quantitative methods where possible, and resolving some of the critical issues involving alternative interpretations. Broader impacts: The scientific impacts of this work are an improved understanding of Antarctic plate tectonic history to incorporate into global models. This project will support one graduate student at each institution. The results of the project will be made available in the global plate motion and plate reconstruction databases. In addition, results will be used for outreach work to middle school groups. Cande has made an animated movie of the plate motions around the Aus-Pac plate circuit that he uses as part of his undergraduate and graduate teaching. He plans to update and expand this animation using the results of this project.