Postdoctoral Fellowship: EAR-PF: Pairing on-and-offshore observations of paleo-ice streams to constrain and elucidate dynamics of the Cordilleran Ice Sheet (PISCES)

Marion McKenzie博士被授予美国国家科学基金会地球科学博士后奖学金，在Ryan Venturelli博士的指导下在科罗拉多矿业学院开展研究和专业发展活动。麦肯齐博士试图解决陆地（陆上）和海洋（近海）冰川记录之间的关系。大约2万年前，当科迪勒拉冰盖（CIS）覆盖北美西部时，控制它的因素还不是很清楚。利用陆上和海上的冰川记录，该项目将提高对太平洋和独联体动态的理解。这项工作还试图深入了解影响冰盖对海平面上升贡献的因素，这将最终有助于限制现代系统中的冰如何在未来对海平面上升做出贡献。奖学金资金为本科生进行研究创造了机会。此外，该项目将支持为大学水平和阿拉斯加本土科学与工程项目学生开发教育材料。尽管这一记录可能有助于确定冰流稳定性的控制因素，阐明千年和全球尺度的气候振荡，以及描述太平洋古洋流动力学，但对科迪勒兰冰盖（CIS）海洋边缘过去5万年的去冰历史却知之甚少。拟议的项目将利用沉积学、地质年代学、地球物理学和冰川学等领域的技术来限制夏洛特女王湾附近残冰流的时空退缩动力学。主要是，研究人员将利用深海钻探项目（DSDP）巡航18号（177站点）的冰山漂流碎片（IRD）和近海海洋沉积物年代学数据，补充激光雷达（LiDAR）冰川地貌测绘和水深高程数据，以限制过去5万年CIS西南冰流活动的位置、行为、时间和速率。将陆上和海上数据进行配对，将得到古冰川的强有力的时空记录，对整个CIS模型、太平洋海洋动力学和千年尺度气候振荡具有重要意义，从而加强对地球气候系统变化的动力学、速率和幅度的理解。在整个工作中使用的多学科技术将提高对冰流控制的理解，适用于预测未来冰损失的动态，最终阐明陆上和海上记录之间的关系。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Dr. Marion McKenzie has been awarded an NSF Earth Sciences Postdoctoral fellowship to carry out research and professional development activities at Colorado School of Mines under the mentorship of Dr. Ryan Venturelli. Dr. McKenzie seeks to resolve relationships between terrestrial (onshore) and marine (offshore) records of glaciation. The factors that controlled the Cordilleran Ice Sheet (CIS) when it covered western North America about 20,000 years ago are not well understood. Using onshore and offshore records of glaciation, this project will improve understanding of Pacific Ocean and CIS dynamics through time. This work also seeks to provide insight into the factors that influence ice sheet contributions to sea level rise, which will ultimately help in constraining how ice in modern systems may contribute to sea level rise in the future. The fellowship funding creates opportunities for undergraduate students to conduct research. In addition, this project will support development of educational materials for college-level and Alaska Native Science & Engineering Program students. The deglacial history of Cordilleran Ice Sheet (CIS) marine margins over the last 50,000 years is poorly constrained despite the potential insights this record may contribute to identifying controls on ice stream stability, elucidating millennial and global-scale climate oscillations, and characterizing paleo-current dynamics across the Pacific Ocean. The proposed project will leverage techniques from the fields of sedimentology, geochronology, geophysics, and glaciology to constrain the spatiotemporal retreat dynamics of relict ice streams near the Queen Charlotte Sound. Principally, the researchers will supplement mapping of glacial geomorphic landforms from LiDAR and bathymetric elevation data with iceberg-rafted debris (IRD) and offshore marine sediment geochronology from Deep Sea Drilling Project (DSDP) cruise 18, site 177 to constrain the location, behavior, timing, and rate of southwestern CIS ice stream activity over the last 50,000 years. Pairing on-and-offshore data will lead to strong temporal and spatial records of paleo-glaciation with implications for overall CIS modelling, ocean dynamics in the Pacific Ocean, and millennial-scale climate oscillations to bolster understanding of dynamics, rates, and magnitude of change in the Earth climate system. Multidisciplinary techniques used throughout this work will improve understanding of controls on ice streams suitable for predicting dynamics of future ice loss to ultimately elucidate the relationship between onshore and offshore records.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.