New insights into the ∼74ka Toba eruption from sulfur isotopes of polar ice cores ...

• Main Authors: Crick, L, Burke, A, Hutchison, W, Kohno, M, Moore, KA, Savarino, J, Doyle, EA, Mahony, S, Kipfstuhl, S, Rae, JWB, Steele, RCJ, Sparks, RSJ, Wolff, EW
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus GmbH 2021
• Subjects: 37 Earth Sciences; 3709 Physical Geography and Environmental Geoscience; 3703 Geochemistry; 3705 Geology; 13 Climate Action; Antarctic; Dronning Maud Land; Greenland; Antarc*; Greenland ice cores; ice core
• Online Access: https://dx.doi.org/10.17863/cam.77172; https://www.repository.cam.ac.uk/handle/1810/329725

Abstract. The ∼74 ka Toba eruption was one of the largest volcanic events of the Quaternary. There is much interest in determining the impact of such a large event, particularly on the climate and hominid populations at the time. Although the Toba eruption has been identified in both land and marine archives as the Youngest Toba Tuff, its precise place in the ice core record is ambiguous. Several volcanic sulfate signals have been identified in both Antarctic and Greenland ice cores and span the Toba eruption 40Ar/39Ar age uncertainty. Here, we measure sulfur isotope compositions in Antarctic ice samples from the Dome C (EDC) and Dronning Maud Land (EDML) ice cores at high temporal resolution across 11 of these potential Toba sulfate peaks to identify candidates with sulfur mass-independent fractionation (S-MIF), indicative of an eruption whose plume reached altitudes at or above the stratospheric ozone layer. Using this method, we identify several candidate sulfate peaks that contain stratospheric sulfur. ...