Patagonian glacier response during the late glacial-Holocene transition

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doi: 10.1126/science.1157215
Author(s): Ackert, Robert P., Jr.; Becker, Richard A.; Singer, Brad S.; Kurz, Mark D.; Caffee, Marc W.; Mickelson, David M.
Author Affiliation(s): Primary:
Harvard University, Department of Earth and Planetary Science, Cambridge, MA, United States
University of Wisconsin-Madison, United States
Woods Hole Oceanographic Institution, United States
Purdue University, United States
Volume Title: Science
Source: Science, 321(5887), p.392-395. Publisher: American Association for the Advancement of Science, Washington, DC, United States. ISSN: 0036-8075 CODEN: SCIEAS
Note: In English. 28 refs.; illus., incl. 1 table, sketch maps
Summary: Whether cooling occurred in the Southern Hemisphere during the Younger Dryas (YD) is key to understanding mechanisms of millennial climate change. Although Southern Hemisphere records do not reveal a distinct climate reversal during the late glacial period, many mountain glaciers readvanced. We show that the Puerto Bandera moraine (50°S), which records a readvance of the Southern Patagonian Icefield (SPI), formed at, or shortly after, the end of the YD. The exposure age (10.8±0.5 thousand years ago) is contemporaneous with the highest shoreline of Lago Cardiel (49°S), which records peak precipitation east of the Andes since 13 thousand years ago. Absent similar moraines west of the Andes, these data indicate an SPI response to increased amounts of easterly-sourced precipitation-reflecting changes in the Southern Westerly circulation-rather than regional cooling.
Year of Publication: 2008
Key Words: 24 Surficial Geology, Quaternary Geology; Absolute age; Alkaline earth metals; Argentina; Be-10; Beryllium; C-14; Carbon; Cenozoic; Chlorine; Cl-36; Dates; Glacial geology; Glaciers; Halogens; Holocene; Ice fields; Ice movement; Isotopes; Lacustrine environment; Lago Argentino; Metals; Microfossils; Miospores; Moraines; Paleo-oceanography; Paleocirculation; Paleoclimatology; Palynomorphs; Patagonia; Pleistocene; Pollen; Quaternary; Radioactive isotopes; Reconstruction; Relative age; South America; Southern Ocean; Southern Patagonian ice field; Upper Pleistocene; Upper Weichselian; Weichselian; Younger Dryas
Coordinates: S503000 S501000 W0720000 W0730000
Record ID: 2008123176
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