A multi-proxy investigation of sediment core GeoB7165-1 and AMS 14C dating points from sediment cores off Conceptión (~ 36°S)

• Main Authors: Mohtadi, Mahyar, Rossel, Pamela E, Lange, Carina Beatriz, Pantoja, Silvio, Böning, Philipp, Repeta, Daniel J, Grunwald, Maik, Lamy, Frank, Hebbeln, Dierk, Brumsack, Hans-Jürgen
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 2010
• Subjects: Center for Marine Environmental Sciences; CHIPAL; CONDOR-Ia; East Pacific; GeoB3302-1; GeoB3359-3; GeoB7139-2; GeoB7165-1; GIK17748-2; Gravity corer (Kiel type); HOTLINE; HYGAPE; MARUM; off Chile; PUCK; SL; SO101; SO101/3_2-1; SO102/1; SO156/2; SO156/3; SO80_4; SO80a; Sonne; South-East Pacific; Antarc*; Antarctic
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.733253; https://doi.org/10.1594/PANGAEA.733253

A high-resolution sea surface temperature and paleoproductivity reconstruction on a sedimentary record collected at 36°S off central-south Chile (GeoB 7165-1, 36°33'S, 73°40'W, 797 m water depth, core length 750 cm) indicates that paleoceanographic conditions changed abruptly between 18 and 17 ka. Comparative analysis of several cores along the Chilean continental margin (30°-41°S) suggests that the onset and the pattern of deglacial warming was not uniform off central-south Chile due to the progressive southward migration of the Southern Westerlies and local variations in upwelling. Marine productivity augmented rather abruptly at 13-14 ka, well after the oceanographic changes.We suggest that the late deglacial increase in paleoproductivity off central-south Chile reflects the onset of an active upwelling system bringing nutrient-rich, oxygen-poor Equatorial SubsurfaceWater to the euphotic zone, and a relatively higher nutrient load of the Antarctic Circumpolar Current. During the Last Glacial Maximum, when the Southern Westerlies were located further north, productivity off central-south Chile, in contrast to off northern Chile, was reduced due to direct onshore-blowing winds that prevented coastal upwelling and export production.