Interhemispheric synchroneity of Marine Oxygen Isotope Stage 2 glacier fluctuations along the American cordilleras transect

This paper reviews the evidence for glacier advances in 11 different regions in the American cordilleras during the interval 40–10 kyr BP. The dating control is still too poor to provide firm constraints, but patterns are beginning to emerge. With the apparent exception of some Mexican volcanoes and the Colombian Andes, there was a period of reduced glaciation at 40–28 kyr BP, followed by an interval of ca. 15 kyr during which three to four glacier advances occurred in most regions. It appears that the main advances are synchronous in parts of both the Southern and Northern Hemispheres, although regional differences occur, probably in response to changes in precipitation and storm tracks. The tightest chronologies reveal an apparent millennial-scale signal throughout the interval spanned by Marine Oxygen Isotope Stage 2.