The influence of Antarctic subglacial volcanism on the global iron cycle during the Last Glacial Maximum

• Published in: Nature Communications
• Main Authors: Frisia, Silvia, Weyrich, Laura S., Hellstrom, John, Borsato, Andrea, Golledge, Nicholas R., Anesio, Alexandre M., Bajo, Petra, Drysdale, Russell N., Augustinus, Paul C., Rivard, Camille, Cooper, Alan
• Other Authors: Univ Newcastle, Sch Environm & Life Sci, Callaghan, NSW 2308, Australia, Univ Adelaide, Australian Ctr Ancient DNA ACAD, Adelaide, SA 5005, Australia, Univ Melbourne, Sch Earth Sci, Parkville, Vic 3010, Australia, GNS Science, Victoria Univ Wellington, Antarctic Res Ctr, Wellington 6140, New Zealand, University of Bristol Bristol, Univ Melbourne, Sch Geog, Parkville, Vic 3010, Australia, Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS), Univ Auckland, Sch Environm, Auckland 92019, New Zealand, European Synchrotron Radiation Facility (ESRF)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: geo; envir; Antarctic; East Antarctic Ice Sheet; Southern Ocean; The Antarctic; Antarc*; Ice Sheet
• Online Access: https://doi.org/10.1038/ncomms15425; https://hal.archives-ouvertes.fr/hal-01692159/file/Nature_Communications_8_15425.pdf; https://hal.archives-ouvertes.fr/hal-01692159

International audience Marine sediment records suggest that episodes of major atmospheric CO2 drawdown during the last glacial period were linked to iron (Fe) fertilization of subantarctic surface waters. The principal source of this Fe is thought to be dust transported from southern mid-latitude deserts. However, uncertainty exists over contributions to CO2 sequestration from complementary Fe sources, such as the Antarctic ice sheet, due to the difficulty of locating and interrogating suitable archives that have the potential to preserve such information. Here we present petrographic, geochemical and microbial DNA evidence preserved in precisely dated subglacial calcites from close to the East Antarctic Ice-Sheet margin, which together suggest that volcanically-induced drainage of Fe-rich waters during the Last Glacial Maximum could have reached the Southern Ocean. Our results support a significant contribution of Antarctic volcanism to subglacial transport and delivery of nutrients with implications on ocean productivity at peak glacial conditions