Collaborative Research: Anisotropy, Abrupt Climate Change, and the Deep Ice in West Antarctica

Pettit/0636795该奖项支持一个项目，该项目使用垂直速度分布来限制Siple Dome的累积速率、厚度和温度历史，该垂直速度分布包括随时间变化的织物对变形的影响，以反演根据Siple Dome薄片中观察到的声速测量和颗粒尺寸确定的织物深度剖面，以了解过去表面温度和累积速率的变化，重点关注22ka和15ka的明显突然气候变化事件。这项工作的学术价值在于，它将使用耦合的组构演化和冰盖流动模型，从深层冰的一系列物理属性中提取过去的气候信息。重点将放在Siple Dome深冰川时代的冰上，那里的冰芯记录显示了令人费解的信号，建模结果表明了有趣的变形模式。该方法还将应用于伯德站和泰勒穹顶的记录，最终形成未来分析西南极分水岭岩芯的基础。该项目更广泛的影响是，它最终将有助于我们了解各向异性对南极洲西部冰流动力学的影响。这将有助于我们理解冰流和冰芯中的古气候记录之间的联系，特别是关于化学记录和冰变形之间的关系。它还将贡献一种新的冰流模型，其中包括各向异性和组构演化的影响。该项目还将有助于推动一名新的、年轻的女性调查员的职业生涯，并将支持几名研究生。最后，这项工作将通过直接帮助支持冰上女孩项目来鼓励物理科学的多样性，该项目鼓励年轻女性探索科学和自然世界。

Pettit/0636795This award supports a project to constrain the accumulation rate, thickness, and temperature history for Siple Dome using a vertical velocity profile that includes the effects of an evolving fabric on deformation through time, to invert the depth-profile of fabric determined from sonic velocity measurements and grain size observed in thin sections in Siple Dome for the surface temperature and accumulation rate changes in the past, focusing on the apparent abrupt climate change events at 22ka and 15ka. The intellectual merit of the work is that it will extract past climate information from a number of physical properties of the deep ice using a coupled fabric evolution and ice-sheet flow model. The focus will be on the deep ice-age ice at Siple Dome, where the ice-core record shows puzzling signals and where modeling results imply intriguing deformation patterns. The method will also be applied to the records from Byrd Station and Taylor Dome to ultimately form a basis for future analysis of the West Antarctic Divide core. The broader impacts of the project are that it will ultimately contribute to our understanding of the effects of anisotropy on ice flow dynamics in West Antarctica. It will contribute to our understanding of the connection between ice flow and the paleoclimate record in ice cores, particularly with respect to the relationship between the chemical record and ice deformation. And it will contribute a new ice-flow model that includes the effects of anisotropy and fabric evolution. The project will also contribute to advancing the career of a new, young, female investigator and will support a couple of graduate students. Finally, the work will encouraging diversity in the physical sciences by directly helping to support the Girls on Ice a program that encourages young women to explore science and the natural world.