Glacier fuctuations in the northern Patagonian Andes (44°S) imply wind‑modulated interhemispheric in‑phase climate shifts during Termination 1

• Published in: Scientific Reports
• Main Authors: Soteres, Rodrigo L., Sagredo, Esteban A., Kaplan, Michael R., Martin, Mateo A., Moreno Moncada, Patricio Iván, Reynhout, Scott Andrew, Schwartz, Roseanne, Schaefer, Joerg M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature 2022
• Subjects: Nuclide production-rates; Chilean lake district; BE-10 production-rate; Southern alps; New-Zealand; Radiocarbon chronology; Isla Grande; East Greenland; European alps; Rakaia Valley; Antarctic; Greenland; isla Grande; Marsden; New Zealand; Patagonia; Southern Ocean; The Antarctic; Antarc*; glacier
• Online Access: https://doi.org/10.1038/s41598-022-14921-4; https://repositorio.uchile.cl/handle/2250/187047

The Last Glacial Termination (T1) featured major changes in global circulation systems that led to a shift from glacial to interglacial climate. While polar ice cores attest to an antiphased thermal pattern at millennial timescales, recent well-dated moraine records from both hemispheres suggest in-phase fluctuations in glaciers through T1, which is inconsistent with the bipolar see-saw paradigm. Here, we present a glacier chronology based on 30 new Be-10 surface exposure ages from well-preserved moraines in the Lago Palena/General Vintter basin in northern Patagonia (similar to 44 degrees S). We find that the main glacier lobe underwent profound retreat after 19.7 +/- 0.7 ka. This recessional trend led to the individualization of the Cerro Rinon glacier by similar to 16.3 ka, which underwent minor readvances at 15.9 +/- 0.5 ka during Heinrich Stadial 1, during the Antarctic Cold Reversal with successive maxima at 13.5 +/- 0.4, 13.1 +/- 0.4, and 13.1 +/- 0.5 ka, and a minor culmination at 12.5 +/- 0.4 ka during Younger Dryas time. We conclude that fluctuations of Patagonian glaciers during T1 were controlled primarily by climate anomalies brought by shifts in the Southern Westerly Winds (SWW) locus. We posit that the global covariation of mountain glaciers during T1 was linked to variations in atmospheric CO2 (atmCO(2)) promoted by the interplay of the SWW-Southern Ocean system at millennial timescales. Comision Nacional de Investigacion Cientifica y Tecnologica 21161417 Millennium Science Initiative/Millennium Nucleus Paleoclimate NCN17_079 Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1160488 1191435 Royal Society Te Aparangi, Marsden Fund VUW-1701 Versión publicada - versión final del editor