A record from Lake Cardiel of climate change in southern South America

Abstract

SOUTHERN South America, the only continental land mass lying between 38° S and the Antarctic Circle, presents a rare opportunity to reconstruct terrestrial records of palaeoclimate in an area that is subject to shifts of polar and mid-latitude wind and pressure belts. In the bulk of this region (Patagonia) are many hydrographically closed lakes which, despite the palaeoclimatic significance of the region and the proven utility of lake level records in reconstructing past climates1,2, have escaped detailed study. Using sedimentary and geomorphic evidence, together with 14C dating, we present here a detailed lake level record for Lake Cardiel (Fig. 1). The highest level of the past >21,000 years occurred at about 9,780 BP, reminiscent of tropical lakes rather than those in northern mid-latitudes1,2. The Lake Cardiel record corroborates and clarifies the timing of the wetness record inferred from pollen studies in Patagonia.