Millennial-scale sea surface temperature and Patagonian Ice Sheet changes off southernmost Chile (53°S) over the past ∼60 kyr

• Published in: Paleoceanography
• Main Authors: Caniupán, M., Lamy, F., Lange, C., Kaiser, J., Arz, H., Kilian, R., Baeza Urrea, O., Aracena, C., Hebbeln, D., Kissel, C., Laj, C., Mollenhauer, G., Tiedemann, R.
• Other Authors: Alfred Wegener Institute for Polar and Marine Research (AWI), Universidad de Concepción - University of Concepcion Chile, Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Trier University, Center for Marine Environmental Sciences Bremen (MARUM), Universität Bremen, Climat et Magnétisme (CLIMAG), Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; Antarctic; Pacific; Southern Ocean; Antarc*; ice core; Ice Sheet; Neogloboquadrina pachyderma; Planktonic foraminifera
• Online Access: https://hal.archives-ouvertes.fr/hal-03118215; https://hal.archives-ouvertes.fr/hal-03118215/document; https://hal.archives-ouvertes.fr/hal-03118215/file/2010PA002049.pdf; https://doi.org/10.1029/2010PA002049

International audience Glacial millennial‐scale paleoceanographic changes in the Southeast Pacific and the adjacent Southern Ocean are poorly known due to the scarcity of well‐dated and high resolution sediment records. Here we present new surface water records from sediment core MD07‐3128 recovered at 53°S off the Pacific entrance of the Strait of Magellan. The alkenone‐derived sea surface temperature (SST) record reveals a very strong warming of ca. 8°C over the last Termination and substantial millennial‐scale variability in the glacial section largely consistent with our planktonic foraminifera oxygen isotope (δ18O) record of Neogloboquadrina pachyderma (sin.). The timing and structure of the Termination and some of the millennial‐scale SST fluctuations are very similar to those observed in the well‐dated SST record from ODP Site 1233 (41°S) and the temperature record from Drowning Maud Land Antarctic ice core supporting the hemispheric‐wide Antarctic timing of SST changes. However, differences in our new SST record are also found including a long‐term warming trend over Marine Isotope Stage (MIS) 3 followed by a cooling toward the Last Glacial Maximum (LGM). We suggest that these differences reflect regional cooling related to the proximal location of the southern Patagonian Ice Sheet and related meltwater supply at least during the LGM consistent with the fact that no longer SST cooling trend is observed in ODP Site 1233 or any SST Chilean record. This proximal ice sheet location is documented by generally higher contents of ice rafted debris (IRD) and tetra‐unsaturated alkenones, and a slight trend toward lighter planktonic δ18O during late MIS 3 and MIS 2.