Late glacial climate evolution in the Patagonian Andes (44-47° S) from alpine glacier modelling
Muir, Ruby
Victoria University Wellington
Eaves, Shaun
Victoria University Wellington
Vargo, Lauren
Victoria University Wellington
Anderson, Brian
Victoria University Wellington
Mackintosh, Andrew
Monash University
Sagredo, Esteban
Pontificia Universidad Catolica de Chile
Soteres, Rodrigo
Journal
Quaternary Science Reviews
ISSN
0277-3791
1873-457X
Open Access
hybrid
Volume
305
Numerical glacier models applied to moraine chronologies provide an opportunity to quantify past climate change. Here we apply a two-dimensional coupled mass balance -ice flow model to well-dated moraine sequences deposited by former alpine glaciers at two central Patagonian sites: Cerro Rinon (43.97 degrees S, 71.64 degrees W) and Rio Tranquilo (47.50 degrees S, 72.38 degrees W), to reconstruct the local temperatures during both the Antarctic Cold Reversal (14.7-13 ka) and the Younger Dryas (12.9-11 ka). Modelled tempera-ture anomalies during the Antarctic Cold Reversal are-2.6 +/- 0.4 degrees C at 44 degrees S, and-2.9 +/- 0.6 degrees C at 47 degrees S. At both locations this cold event is followed by temperature increases of +0.6-0.7 degrees C or precipitation re-ductions of c. 20% to drive glacier retreat to moraines deposited during Younger Dryas time. The consistent climatic anomalies between these two latitudes suggest this region of Patagonia was responding to a common climatic event. Further, the late-glacial temperature anomalies found here compare well to those determined by similar glacier modelling techniques in New Zealand, at 43-44 degrees S. These results support a trans-Pacific response throughout the southern mid to high latitudes (43-47 degrees S) during the ACR that is best explained by a northward expansion of the south westerly winds.(c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).