Biomarker proxies on sediment cores in the central Arctic Ocean

• Main Authors: Stein, Ruediger, Fahl, Kirsten, Schreck, Michael, Knorr, Gregor, Niessen, Frank, Forwick, Matthias, Gebhardt, Andrea Catalina, Jensen, Laura, Kaminski, Michael Anthony, Kopf, Achim J, Matthiessen, Jens, Jokat, Wilfried, Lohmann, Gerrit, PS87 Geoscience Party
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 2015
• Subjects: AWI_Paleo; Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP; Ocean Drilling Program; ODP; Paleoenvironmental Reconstructions from Marine Sediments @ AWI; Arctic; Arctic Ocean; Lomonosov Ridge; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.855509; https://doi.org/10.1594/PANGAEA.855509

Although the permanently to seasonally ice-covered Arctic Ocean is a unique and sensitive component in the Earth's climate system, the knowledge of its long-term climate history remains very limited due to the restricted number of pre-Quaternary sedimentary records. During Polarstern Expedition PS87/2014, we discovered multiple submarine landslides over a distance of >350 km along Lomonosov Ridge. Removal of younger sediments from steep headwalls has led to exhumation of Miocene to early Quaternary sediments close to the seafloor, allowing the retrieval of such old sediments with gravity cores. Multi-proxy biomarker analyses of these gravity cores reveal for the first time that the late Miocene central Arctic Ocean was relatively warm (4-7°C) and ice-free during summer, whereas sea ice occurred during spring and autumn/winter. A comparison of our proxy data with Miocene climate simulations seems to favour relatively high late Miocene atmospheric CO2 concentrations. These new findings from the Arctic region provide new benchmarks for groundtruthing global climate reconstructions and modeling.