Geochemical response of the mid-depth Northeast Atlantic Ocean to freshwater input during Heinrich events 1 to 4

Heinrich events are intervals of rapid iceberg-sourced freshwater release to the high latitude North Atlantic Ocean that punctuate late Pleistocene glacials. Delivery of fresh water to the main North Atlantic sites of deep water formation during Heinrich events may result in major disruption to the...

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Published in:Quaternary Science Reviews
Main Authors: Crocker, Anya J., Chalk, Thomas B., Bailey, Ian, Spencer, Megan R., Gutjahr, Marcus, Foster, Gavin L., Wilson, Paul A.
Format: Article in Journal/Newspaper
Language:English
Published: 2016
Subjects:
Online Access:https://eprints.soton.ac.uk/401247/
https://eprints.soton.ac.uk/401247/1/Crocker%2520et%2520al%252016%2520QSR%2520for%2520REF.pdf
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spelling ftsouthampton:oai:eprints.soton.ac.uk:401247 2024-02-11T10:06:02+01:00 Geochemical response of the mid-depth Northeast Atlantic Ocean to freshwater input during Heinrich events 1 to 4 Crocker, Anya J. Chalk, Thomas B. Bailey, Ian Spencer, Megan R. Gutjahr, Marcus Foster, Gavin L. Wilson, Paul A. 2016-11-01 text https://eprints.soton.ac.uk/401247/ https://eprints.soton.ac.uk/401247/1/Crocker%2520et%2520al%252016%2520QSR%2520for%2520REF.pdf en English eng https://eprints.soton.ac.uk/401247/1/Crocker%2520et%2520al%252016%2520QSR%2520for%2520REF.pdf Crocker, Anya J., Chalk, Thomas B., Bailey, Ian, Spencer, Megan R., Gutjahr, Marcus, Foster, Gavin L. and Wilson, Paul A. (2016) Geochemical response of the mid-depth Northeast Atlantic Ocean to freshwater input during Heinrich events 1 to 4. Quaternary Science Reviews, 151, 236-254. (doi:10.1016/j.quascirev.2016.08.035 <http://dx.doi.org/10.1016/j.quascirev.2016.08.035>). accepted_manuscript Article PeerReviewed 2016 ftsouthampton https://doi.org/10.1016/j.quascirev.2016.08.035 2024-01-25T23:19:03Z Heinrich events are intervals of rapid iceberg-sourced freshwater release to the high latitude North Atlantic Ocean that punctuate late Pleistocene glacials. Delivery of fresh water to the main North Atlantic sites of deep water formation during Heinrich events may result in major disruption to the Atlantic Meridional Overturning Circulation (AMOC), however, the simple concept of an AMOC shutdown in response to each freshwater input has recently been shown to be overly simplistic. Here we present a new multi-proxy dataset spanning the last 41,000 years that resolves four Heinrich events at a classic mid-depth North Atlantic drill site, employing four independent geochemical tracers of water mass properties: boron/calcium, carbon and oxygen isotopes in foraminiferal calcite and neodymium isotopes in multiple substrates. We also report rare earth element distributions to investigate the fidelity by which neodymium isotopes record changes in water mass distribution in the northeast North Atlantic. Our data reveal distinct geochemical signatures for each Heinrich event, suggesting that the sites of fresh water delivery and/or rates of input played at least as important a role as the stage of the glacial cycle in which the fresh water was released. At no time during the last 41 kyr was the mid-depth northeast North Atlantic dominantly ventilated by southern-sourced water. Instead, we document persistent ventilation by Glacial North Atlantic Intermediate Water (GNAIW), albeit with variable properties signifying changes in supply from multiple contributing northern sources. Article in Journal/Newspaper North Atlantic Northeast Atlantic University of Southampton: e-Prints Soton Quaternary Science Reviews 151 236 254
institution Open Polar
collection University of Southampton: e-Prints Soton
op_collection_id ftsouthampton
language English
description Heinrich events are intervals of rapid iceberg-sourced freshwater release to the high latitude North Atlantic Ocean that punctuate late Pleistocene glacials. Delivery of fresh water to the main North Atlantic sites of deep water formation during Heinrich events may result in major disruption to the Atlantic Meridional Overturning Circulation (AMOC), however, the simple concept of an AMOC shutdown in response to each freshwater input has recently been shown to be overly simplistic. Here we present a new multi-proxy dataset spanning the last 41,000 years that resolves four Heinrich events at a classic mid-depth North Atlantic drill site, employing four independent geochemical tracers of water mass properties: boron/calcium, carbon and oxygen isotopes in foraminiferal calcite and neodymium isotopes in multiple substrates. We also report rare earth element distributions to investigate the fidelity by which neodymium isotopes record changes in water mass distribution in the northeast North Atlantic. Our data reveal distinct geochemical signatures for each Heinrich event, suggesting that the sites of fresh water delivery and/or rates of input played at least as important a role as the stage of the glacial cycle in which the fresh water was released. At no time during the last 41 kyr was the mid-depth northeast North Atlantic dominantly ventilated by southern-sourced water. Instead, we document persistent ventilation by Glacial North Atlantic Intermediate Water (GNAIW), albeit with variable properties signifying changes in supply from multiple contributing northern sources.
format Article in Journal/Newspaper
author Crocker, Anya J.
Chalk, Thomas B.
Bailey, Ian
Spencer, Megan R.
Gutjahr, Marcus
Foster, Gavin L.
Wilson, Paul A.
spellingShingle Crocker, Anya J.
Chalk, Thomas B.
Bailey, Ian
Spencer, Megan R.
Gutjahr, Marcus
Foster, Gavin L.
Wilson, Paul A.
Geochemical response of the mid-depth Northeast Atlantic Ocean to freshwater input during Heinrich events 1 to 4
author_facet Crocker, Anya J.
Chalk, Thomas B.
Bailey, Ian
Spencer, Megan R.
Gutjahr, Marcus
Foster, Gavin L.
Wilson, Paul A.
author_sort Crocker, Anya J.
title Geochemical response of the mid-depth Northeast Atlantic Ocean to freshwater input during Heinrich events 1 to 4
title_short Geochemical response of the mid-depth Northeast Atlantic Ocean to freshwater input during Heinrich events 1 to 4
title_full Geochemical response of the mid-depth Northeast Atlantic Ocean to freshwater input during Heinrich events 1 to 4
title_fullStr Geochemical response of the mid-depth Northeast Atlantic Ocean to freshwater input during Heinrich events 1 to 4
title_full_unstemmed Geochemical response of the mid-depth Northeast Atlantic Ocean to freshwater input during Heinrich events 1 to 4
title_sort geochemical response of the mid-depth northeast atlantic ocean to freshwater input during heinrich events 1 to 4
publishDate 2016
url https://eprints.soton.ac.uk/401247/
https://eprints.soton.ac.uk/401247/1/Crocker%2520et%2520al%252016%2520QSR%2520for%2520REF.pdf
genre North Atlantic
Northeast Atlantic
genre_facet North Atlantic
Northeast Atlantic
op_relation https://eprints.soton.ac.uk/401247/1/Crocker%2520et%2520al%252016%2520QSR%2520for%2520REF.pdf
Crocker, Anya J., Chalk, Thomas B., Bailey, Ian, Spencer, Megan R., Gutjahr, Marcus, Foster, Gavin L. and Wilson, Paul A. (2016) Geochemical response of the mid-depth Northeast Atlantic Ocean to freshwater input during Heinrich events 1 to 4. Quaternary Science Reviews, 151, 236-254. (doi:10.1016/j.quascirev.2016.08.035 <http://dx.doi.org/10.1016/j.quascirev.2016.08.035>).
op_rights accepted_manuscript
op_doi https://doi.org/10.1016/j.quascirev.2016.08.035
container_title Quaternary Science Reviews
container_volume 151
container_start_page 236
op_container_end_page 254
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