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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 (5005), 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. [ABSTRACT FROM AUTHOR]

The article provides information on a study conducted by Robert P. Ackert Jr. and colleagues in order to determine whether or not southern Patagonia's glacial advance that created it occurred during the chronozone of the Younger Dryas. It mentions that the Ackert and colleagues measured the cosmic-ray exposure ages of the southern Patagonia's glacial moraine. Soon after the end of the Younger Dryas, moraine was deposited followed by the growth of the glacier in response to more precipitation. This suggests that Southern Hemisphere's temperature did not drop like those in the Northern Hemisphere during the Younger Dryas.