Reconstruction of the variability of the Kuroshio Ocean Current (SE Japan) over the past 8 Ma

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The Kuroshio Ocean current (KOC) is the large north-western component of the subtropical North Pacific Ocean gyre and of major importance in the meridional transport of heat, mass, momentum, and moisture from the western Pacific warm pool to the northern mid-latitudes. Variation of shape, intensity and position of the KOC alternate over millennial timescales and significantly impact the climate of Japan and Asia. The main objective of the present proposal is the generation of a continuous, high resolution climate record of the present-day to Late Miocene in the western subtropical Pacific region. For this, we aim on investigating deep-sea sediments (Core C0011) of the Nankai Trough (SE-Japan) recovered during IODP Expedition 333 with bulk organic-geochemical and isotope techniques as well as lipid biomarker distributions. Bulk TOC, TOC/TN and δ13CTOC values will be generated to identify climate induced perturbations of the marine carbon-cycle. These intervals as well as the long-term climate evolution of the north-western Pacific will be studied in detail using the distribution of glycerol dialkyl glycerol tetraethers (GDGTs) that allow the reconstruction of past sea surface temperatures. This molecular palaeothermometer proxy will be complemented by the use of unsaturated alkenones in the uppermost section of the core covering the last 250 ka. The generation of detailed SST curves will allow the in-depth study of climate evolution of the north-western Pacific, which is envisaged to be directly linked to the migration pattern of the Kuroshio Ocean Current.