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

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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.