Northern Hemisphere insolation intensity is roughly in phase with Southern Hemisphere climate proxies, leading to a common conclusion that northern insolation forces southern climate during the Late Quaternary. However, mid-latitude Southern Hemisphere records place the advance of Patagonian and New Zealand glaciers before the Last Glacial Maximum (29,000–18,000 years ago) by several millennia. To resolve the cause(s) of nearly synchronous global climate change requires continuous archives of mid-latitude glacial activity for the last glacial cycle. Here we assess the position of the Patagonian Ice Sheet’s marine-terminating margin over the last ~89,000 years using a sedimentary-beryllium-isotope record from the Chilean margin to track the proximity of local glaciers. We find that glaciations and deglaciations are synchronous with or precede Northern Hemisphere ice sheets by thousands of years. Glacial expansion was driven by equatorward migration and strengthening of the southern westerly winds, linked to global cooling and a steeper meridional temperature gradient. Glacial terminations occurred when global warming coincided with increasing obliquity and dramatic Northern Hemisphere cooling. Our results suggest that, on orbital timescales, a complex interaction between mean global climate, obliquity and interhemispheric teleconnections could have led to near-synchronous global ice sheet evolution through displacements of the southern westerlies.

北半球日照强度与南半球气候代理大致同步，得出一个共同结论，即晚第四纪期间北半球日照强度迫使南方气候。然而，南半球中纬度地区的记录表明，巴塔哥尼亚和新西兰冰川的推进早于末次盛冰期（29,000-18,000年前）数千年。为了解决几乎同步的全球气候变化的原因，需要对上一个冰川周期的中纬度冰川活动进行连续档案。在这里，我们使用智利边缘的沉积铍同位素记录来跟踪当地冰川的接近程度，评估了过去约 89,000 年巴塔哥尼亚冰盖海洋终止边缘的位置。我们发现冰川作用和冰消作用与北半球冰盖同步或早数千年。冰川扩张是由赤道迁移和南风加强驱动的，与全球变冷和更陡的经向温度梯度有关。当全球变暖与倾斜度增加和北半球急剧变冷同时发生时，冰川终止就会发生。我们的结果表明，在轨道时间尺度上，全球平均气候、倾角和半球间遥相关之间的复杂相互作用可能通过南西风带的位移导致全球冰盖近乎同步的演化。