High-precision 10Be chronology of moraines in the Southern Alps indicates synchronous cooling in Antarctica and New Zealand 42,000 years ago ...

• Main Authors: Kelley, Samuel E., Kaplan, Michael, Andersen, Bjørn G., Schaefer, Joerg M., Barrell, David J. A., Putnam, Aaron Ervin, Denton, George H., Schwartz, Roseanne G., Finkel, Robert C., Doughty, Alice M.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Columbia University 2014
• Subjects: Paleoclimatology; Climatic changes; Geomorphology; Atmosphere; Greenland; New Zealand; Pukaki; Antarc*; glacier; Greenland ice cores
• Online Access: https://dx.doi.org/10.7916/d8tb169t; https://academiccommons.columbia.edu/doi/10.7916/D8TB169T

Millennial-scale temperature variations in Antarctica during the period 80,000 to 18,000 years ago are known to anti-correlate broadly with winter-centric cold–warm episodes revealed in Greenland ice cores. However, the extent to which climate fluctuations in the Southern Hemisphere beat in time with Antarctica, rather than with the Northern Hemisphere, has proved a controversial question. In this study we determine the ages of a prominent sequence of glacial moraines in New Zealand and use the results to assess the phasing of millennial climate change. Forty-four 10Be cosmogenic surface-exposure ages of boulders deposited by the Pukaki glacier in the Southern Alps document four moraine-building events from Marine Isotope Stage 3 (MIS 3) through to the end of the Last Glacial Maximum (∼18,000 years ago; LGM). The earliest moraine-building event is defined by the ages of nine boulders on a belt of moraine that documents the culmination of a glacier advance 42,000 years ago. At the Pukaki locality this advance ...