Glacier expansion in southern Patagonia throughout the Antarctic cold reversal

• Published in: Geology
• Main Authors: Garcia, Juan L., Kaplan, Michael R., Hall, Brenda L., Schaefer, Joerg M., Vega, Rodrigo M., Schwartz, Roseanne, Finkel, Robert
• Format: Article in Journal/Newspaper
• Language: English
• Published: GEOLOGICAL SOC AMER, INC 2024
• Subjects: BE-10 PRODUCTION-RATE; ATMOSPHERIC CO2; NEW-ZEALAND; LAST DEGLACIATION; CLIMATE-CHANGE; TERMINATION; FLUCTUATIONS; HOLOCENE; CHRONOLOGY; GREENLAND; 13 Climate Action; 13 Acción por el clima; Antarctic; Southern Ocean; The Antarctic; Patagonia; Greenland; New Zealand; Magallanes; Paine; Antarc*; Antarctica; glacier
• Online Access: https://repositorio.uc.cl/handle/11534/77163; https://doi.org/10.1130/G33164.1

Resolving debated climate changes in the southern middle latitudes and potential teleconnections between southern temperate and polar latitudes during the last glacial-interglacial transition is required to help understand the cause of the termination of ice ages. Outlet glaciers of the Patagonian Ice Fields are primarily sensitive to atmospheric temperature and also precipitation, thus former ice margins record the extent and timing of past climate changes. 38 Be-10 exposure ages from moraines show that outlet glaciers in Torres del Paine (51 degrees S, south Patagonia, Chile) advanced during the time of the Antarctic cold reversal (ACR; ca. 14.6-12.8 ka), reaching a maximum extent by similar to 14,200 +/- 560 yr ago. The evidence here indicates that the South Patagonian Ice Field was responding to late glacial climate change distinctly earlier than the onset of the European Younger Dryas stadial (ca. 12.9 ka). Major glacier recession and deglaciation in the Torres del Paine region occurred by 12.5 ka and thus early in the Younger Dryas. We provide direct evidence for extensive ice in Patagonia at the very start of the ACR that agrees with atmospheric and marine records from the Southern Ocean and Antarctica. Atmospheric conditions responsible for the early late glacial expansion at Torres del Paine resulted from a climate reorganization that prompted a northern migration of the south westerly wind belt to the latitude of Torres del Paine at the onset of the ACR chronozone. National Geographic Society Churchill Exploration Fund Graduate Student Government at the University of Maine Corner Science and Education Foundation CONAF (Corporacion Nacional Forestal) Region de Magallanes Torres del Paine National Park (Chile)