Last Glacial Maximum and Hypsithermal in the Southern Hemisphere

A synthesis of the two contrasting climates of the upper Quaternary in the Southern Hemisphere, based on continental geological indicators, suggests that the Antarctic Anticyclone is the most important climatic system in the hemisphere. According to glaciological and oceanographic studies, the Antarctic Anticyclone covered an area in the LGM that was double of that during the Hypsithermal. This phenomenon produced a consequent shifting of the climatic belts by approximately 10° of latitude to the north in the LGM and a migration to the south during the Hypsithermal. Oceanic and continental anticyclones were active systems in shaping climates in South America, Australasia, and Southern Africa. These structures were enhanced throughout the LGM (provoking generalized droughts), and weakened at the Hypsithermal (permitting more rains in tropical latitudes). The results presented here were obtained by integrating our own results with regional and continental syntheses of other authors. The paleoclimatic proposals are amply validated by more than 1500 dates in the four continents. Geological and geomorphological features, such as dunefields, paleosols, fluvial terraces and lake levels were the main tools employed in the work.