학술논문

Glacier expansion in southern Patagonia throughout the Antarctic Cold Reversal
Document Type
Academic Journal
Source
Geology (Boulder). 40(9):859-862
Subject
24|Quaternary geology
alkaline earth metals
Amarga Lake
Antarctic Cold Reversal
Azul Lake
Be-10
beryllium
boulders
Cenozoic
Chile
clastic sediments
climate change
deglaciation
exposure age
geochronology
glacial extent
glacial geology
glaciers
ice movement
isotopes
metals
moraines
paleoclimatology
Patagonia
Pleistocene
Quaternary
radioactive isotopes
Sarmiento Lake
sediments
South America
Torres del Paine National Park
upper Pleistocene
upper Weichselian
Weichselian
Younger Dryas
Language
English
ISSN
0091-7613
Abstract
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 10Be exposure ages from moraines show that outlet glaciers in Torres del Paine (51°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 ∼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.