Glacier advance in southern middle-latitudes during the Antarctic Cold Reversal

During the last deglaciation, warming over Antarctica was interrupted by a return to colder conditions from about 14,540 to 12,760 yr ago. This period, known as the Antarctic Cold Reversal, is well documented in Antarctic ice cores(1), but the geographic extent of the cooling throughout the Southern Hemisphere remains unclear(2). Here we use Be-10 surface-exposure ages from two glacial moraine sets from the Southern Alps, New Zealand, to assess whether the glacier advance was associated with the Antarctic Cold Reversal. We find that widespread glacier resurgence culminated 13,000 years ago, at the peak of Antarctic cooling. Subsequent glacier retreat in the Southern Alps coincided with warming in Antarctica. We conclude that the climate deterioration associated with the Antarctic Cold Reversal extended into the southern mid-latitudes of the southwestern Pacific Ocean. We suggest that the extensive cooling was caused by northward migration of the southern Subtropical Front, and concomitant northward expansion of cold Southern Ocean waters.