Temperature and precipitation record in southern Chile extended to ∼43,000 yr ago

Abstract

Southern Chile (41–56 °S), in the belt of westerly winds, receives mostly heavy precipitation, reaching 8,500 mm yr⁻¹ near 50 °S and decreasing northwards and southwards from this latitude to ≤1,500 mm; mean January (summer) temperatures near sea level along the latitudinal gradient are 8–16 °C (refs 1, 2). Dense rain forest covers much of the region to 48 °S; south to Cape Horn, magellanic moorland prevails and rain forest becomes limited. Modern pollen measured in surface samples reflects the distribution of plant species in the vegetation. We have now applied regression equations relating present-day pollen to temperature and precipitation to fossil pollen data at Taiquemó to assess climatic conditions during the Quaternary. The results extend our previous record of the past 16,000 yr at Alerce³ beyond the lateglacial to ∼43,000 yr BP. For the 27,000-yr interval, they show mean January temperatures of 10–12 °C and mean annual precipitation centred around 1,000 mm except during the time span of ∼31,000–43,000 yr BP when amounts increased to 4,000 mm. In general fluctuations correspond to the isotopic climatic reconstruction in Antarctica⁴ and to changes inferred from pollen data at comparable latitudes in Tasmania^5–8 and New Zealand^9,10.