Plio-Pleistocene Environmental and Climatic conditions in the Gulf of Alaska

PECA研究项目的重点是研究阿拉斯加湾上更新世的环境和气候条件(PECA)。通过对IODP探险341(南阿拉斯加大陆边缘)期间采集的沉积物岩心进行有机地球化学块状沉积物分析和生物标志物分析，重建了亚极地东北太平洋的海面条件(如海表面温度、海冰覆盖率、初级生产力)。此外，复合特定同位素分析可以间接估计陆地上的植被(因此也就是气候)。我们的目标是确定北太平洋和北大西洋古海洋环境的短期和长期变化之间的遥相关，以更好地了解它们如何驱动和放大全球气候变异性--与IODP相关的气候研究的一个主要兴趣。PECA项目的目标特别是在北半球冰川加剧期间高度分辨率地重建阿拉斯加湾的古海洋和环境条件，这些冰川与更新世-更新世过渡(约2.7Ma前)、中更新世过渡(约1.2Ma-0.7Ma前)和晚更新世(过去50.000年)有关。确定海冰和海面温度波动以及海洋与大气之间热量和水分交换的相关变化是主要目标，也将为了解西北科迪勒兰冰盖的冰川动力学提供宝贵信息。此外，通过分析保存在海洋沉积物中的陆源有机质的数量和质量，我们将获得关于1)陆地植被和降水/温度变化的信息，以及2)陆源沉积物向阿拉斯加湾的侵蚀和极高的输移率的信息。

The research project PECA focuses on the examination of the Plio-Pleistocene Environmental and Climatic conditions in the Gulf of Alaska (PECA). The sea surface conditions (e.g. sea surface temperatures, sea ice coverage, primary productivity) in the subpolar Northeast Pacific are reconstructed by means of organic geochemical bulk sediment and biomarker analyses of sediment cores recovered during IODP expedition 341 (South Alaska continental margin). In addition, compound specific isotope analyses allow indirect estimates about the vegetation (and thus the climate) on land. We target at the identification of teleconnections between short- and long-term variations in the palaeoceanographic setting in the North Pacific and the North Atlantic to better understand how they drive and amplify global climate variability - a key interest of IODP-related climate research. The PECA project particularly aims at a highly resolved reconstruction of the palaeoceanographic and environmental conditions in the Gulf of Alaska during the intensification of the Northern Hemisphere Glaciation associated with the Plio-Pleistocene Transition (ca. 2.7 Ma ago), the Mid Pleistocene Transition (ca. 1.2 - 0.7 Ma ago), and the Late Pleistocene (the past 50.000 years). The identification of sea ice and sea surface temperature fluctuations and associated changes in the heat and moisture exchange between the ocean and the atmosphere are the main target and will also provide valuable information for the understanding of the glacial dynamics of the Northwestern Cordilleran Ice sheet. Furthermore, by analysing the quantity and quality of terrigenous organic matter preserved within the marine sediments we will yield information about 1) the terrestrial vegetation and precipitation/temperature changes and 2) the erosion and exceptional high transport rates of terrigenous sediments to the Gulf of Alaska.