COLLABORATIVE RESEARCH: Using plate circuits to constrain motion between East and West Antarctica

这项建议将讨论东南极洲和西南极洲之间的运动。对晚白垩纪和新生代运动的估计来自于将连接东南极洲和澳大利亚、Lord Howe隆起、太平洋板块和西南极洲的板块环路加起来。然而，该地区板块运动的历史仍然存在主要的不确定性，导致对全球板块回路的影响大相径庭，没有明确的迹象表明哪种模型是正确的。pi建议分两部分来分析这一运动：42 Ma之后的运动和42 Ma之前的运动。对于较年轻的时间间隔，pi将通过利用一种不寻常的板几何形状来提高旋转的精度，这种几何形状使它们能够解决五边界，四板的配置。对于较早的时间间隔，计算东西南极洲之间运动的唯一方法是通过长长的澳太平洋板块环路。这个时间间隔的困难在于，对于Aus-East蚂蚁边界，有三组旋转，结果截然不同。在50 Ma之前，Aus和Ant在基本运动上的分歧导致了西罗斯海和埃尔斯沃思地附近预测运动的巨大差异。pi建议重新检查au - 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提高对南极板块构造历史的理解，将其纳入全球模式。该项目将资助每所院校的一名研究生。该项目的结果将在全球板块运动和板块重建数据库中提供。此外，结果将用于向中学团体进行推广工作。坎德制作了一部关于Aus-Pac板块电路周围板块运动的动画电影，作为他本科和研究生教学的一部分。他计划使用这个项目的结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.