Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published September 19, 2017 | Supplemental Material + Published
Journal Article Open

Synchronous volcanic eruptions and abrupt climate change ∼17.7 ka plausibly linked by stratospheric ozone depletion

Abstract

Glacial-state greenhouse gas concentrations and Southern Hemisphere climate conditions persisted until ∼17.7 ka, when a nearly synchronous acceleration in deglaciation was recorded in paleoclimate proxies in large parts of the Southern Hemisphere, with many changes ascribed to a sudden poleward shift in the Southern Hemisphere westerlies and subsequent climate impacts. We used high-resolution chemical measurements in the West Antarctic Ice Sheet Divide, Byrd, and other ice cores to document a unique, ∼192-y series of halogen-rich volcanic eruptions exactly at the start of accelerated deglaciation, with tephra identifying the nearby Mount Takahe volcano as the source. Extensive fallout from these massive eruptions has been found >2,800 km from Mount Takahe. Sulfur isotope anomalies and marked decreases in ice core bromine consistent with increased surface UV radiation indicate that the eruptions led to stratospheric ozone depletion. Rather than a highly improbable coincidence, circulation and climate changes extending from the Antarctic Peninsula to the subtropics—similar to those associated with modern stratospheric ozone depletion over Antarctica—plausibly link the Mount Takahe eruptions to the onset of accelerated Southern Hemisphere deglaciation ∼17.7 ka.

Additional Information

© 2017 the Author(s). Published by PNAS. This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND). https://creativecommons.org/licenses/by-nc-nd/4.0/ Edited by Wallace S. Broecker, Columbia University, Palisades, NY, and approved August 7, 2017 (received for review April 5, 2017). Published ahead of print September 5, 2017. We acknowledge R. von Glasow for help with snowpack model simulations, and J. Stutz and R. Kreidberg for helpful discussions. The US National Science Foundation supported this work [Grants 0538427, 0839093, and 1142166 (to J.R.M.); 1043518 (to E.J.B.); 0538657 and 1043421 (to J.P. Severinghaus); 0538553 and 0839066 (to J.C.-D.); and 0944348, 0944191, 0440817, 0440819, and 0230396 (to K.C.T.)]. We thank the WAIS Divide Science Coordination Office and other support organizations. P.K. and G.K. were funded by Polar Regions and Coasts in a Changing Earth System-II, with additional support from the Helmholtz Climate Initiative. Author contributions: J.R.M. designed research; J.R.M., A.B., N.W.D., P.K., J.L.T., M.M.A., N.J.C., O.J.M., M.S., J.F.A., D.B., J.F.B., E.J.B., J.C.-D., T.J.F., G.K., M.M.G., N.I., K.C.M., R.M., G.P., R.H.R., E.S.S., J.P. Severinghaus, J.P. Steffensen, K.C.T., and G.W. performed research; J.R.M. contributed new reagents/analytic tools; J.R.M., A.B., N.W.D., P.K., J.L.T., M.S., E.J.B., C.B., J.C.-D., G.K., H.-F.G., N.I., K.C.M., and G.W. analyzed data; and J.R.M., A.B., N.W.D., P.K., J.L.T., E.J.B., C.B., H.-F.G., and G.W. wrote the paper. The authors declare no conflict of interest. This article is a PNAS Direct Submission. Data deposition: The data reported in this work have been deposited with the U.S. Antarctic Program Data Center, www.usap-dc.org/view/dataset/601008. This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1705595114/-/DCSupplemental.

Attached Files

Published - PNAS-2017-McConnell-10035-40.pdf

Supplemental Material - pnas.1705595114.sapp.pdf

Supplemental Material - pnas.1705595114.sd01.xlsx

Files

pnas.1705595114.sapp.pdf
Files (8.9 MB)
Name Size Download all
md5:4e4c62c06544f248dbf4b305c5107724
1.3 MB Download
md5:d9527b142a94d555433da1f37434941f
6.2 MB Preview Download
md5:21ef1f51dffae0c549b7c321103a5607
1.4 MB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 17, 2023