Doctoral Dissertation Research: Towards Developing a Chronology of Late-Pleistocene Climate Change, Western U.S.: Establishing Production Rates of Cosmogenic Nuclides

高轨道频率的显著气候变率现在被认为是北大西洋周围地区晚更新世冰和沉积物记录中的一个重要信号。其他地方的记录也揭示了千年时间尺度上的气候变化，并确定了重要但鲜为人知的气候变化机制。这个博士论文项目将研究美国西部晚更新世冰川的记录。更好地确定记录的年代和识别其相关气候信号的机制是目标，这将导致对该地区气候变化的时空范围有更全面的了解。目的是利用新开发的地表暴露方法开发一种改进的山地冰川数值年代学，并将其应用于美国西部山脉的众多冰川冰碛。主要目标是通过放射性碳定年流确定宇宙形成核素的生产速率。研究结果将为我们理解不同山脉之间的地层复杂性提供新的线索。它还将有助于揭示过去5万年来该地区的气候变化。

Licciardi, Joseph M Oregon State University Significant climate variability at higher-than-orbital frequencies is now recognized as an important signal in late Pleistocene ice and sediment records from the circum-North Atlantic region. Records elsewhere also reveal climate variability at millennial timescales and identify important but poorly understood mechanisms of climate change. This doctoral dissertation project will examine the record of late-Pleistocene glaciers in the western U.S. Better dating of the record and identification of the mechanisms of its associated climate signal are objectives which will lead to a fuller understanding of the spatial and temporal ranges of climate change in this region. The intent is to develop an improved numerical chronology of mountain glaciation using newly developed surface exposure methods and apply these to numerous glacial moraines in mountain ranges of the western U.S. The primary objective is to establish production rates of cosmogenic nuclides from radiocarbon-dated flows. Results of the research will shed new light on our understanding of stratigraphic complexity from one mountain range to another. It will also serve to reveal the variation in climate in this region over the past 50,000 years.