1. US Geological Survey, 3215 Marine Street, Boulder, Colorado80303 , USA
2. Cornell Laboratory for Stable Isotope Analysis, 125 Boyce Thompson Institute, Tower Road, Cornell University, Ithaca, New York14583, USA
3. Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA
4. Lawrence Livermore National Laboratory , PO Box 808, Livermore, California 94550, USA
5. Department of Geography, University of Nevada, Reno, Nevada89557, USA

Correspondence to: Larry Benson¹ Correspondence and requests for materials should be addressed to L.B. (e-mail: Email: lbenson@usgs.gov).

Abstract

The climate of the North Atlantic region underwent a series of abrupt cold/warm oscillations when the ice sheets of the Northern Hemisphere retreated during the last glacial termination (17.7–11.5kyr ago). Evidence for these oscillations, which are recorded in European terrestrial sediments as the Oldest Dryas/Bølling/Older Dryas/Allerød/Younger Dryas vegetational sequence¹,², has been found in Greenland ice cores³,⁴. The geographical extent of many of these oscillations is not well known⁵,⁶, but the last major cold event (the Younger Dryas) seems to have been global in extent^{7, 8, 9, 10}. Here we present evidence of four major oscillations in the hydrological balance of the Owens basin, California, that occurred during the last glacial termination. Dry events in western North America occurred at approximately the same time as cold events recorded in Greenland ice, with transitions between climate regimes in the two regions taking place within a few hundred years of each other. Our observations thus support recent climate simulations which indicate that cooling of the North Atlantic Ocean results in cooling of the North Pacific Ocean¹¹ which, in turn, leads to a drier climate in western North America¹².