Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition
The ~100 k.y. cyclicity of the late Pleistocene ice ages started during the mid-Pleistocene transition (MPT), as ice sheets became larger and persisted for longer. The climate system feedbacks responsible for introducing this nonlinear ice sheet response to orbital variations in insolation remain un...
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Geological Society of America
2016
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Online Access: | https://orca.cardiff.ac.uk/id/eprint/95508/ https://doi.org/10.1130/G38636.1 https://orca.cardiff.ac.uk/id/eprint/95508/1/Geology-2016-Lear-G38636.1.pdf |
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ftunivcardiff:oai:https://orca.cardiff.ac.uk:95508 2023-05-15T16:41:23+02:00 Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition Lear, Caroline H. Billups, Katharina Rickaby, Rosalind E. M. Diester-Haass, Liselotte Mawbey, Elaine M. Sosdian, Sindia M. 2016-12-01 application/pdf https://orca.cardiff.ac.uk/id/eprint/95508/ https://doi.org/10.1130/G38636.1 https://orca.cardiff.ac.uk/id/eprint/95508/1/Geology-2016-Lear-G38636.1.pdf en eng Geological Society of America https://orca.cardiff.ac.uk/id/eprint/95508/1/Geology-2016-Lear-G38636.1.pdf Lear, Caroline H. https://orca.cardiff.ac.uk/view/cardiffauthors/A048848V.html orcid:0000-0002-7533-4430 orcid:0000-0002-7533-4430, Billups, Katharina, Rickaby, Rosalind E. M., Diester-Haass, Liselotte, Mawbey, Elaine M. https://orca.cardiff.ac.uk/view/cardiffauthors/A127259H.html and Sosdian, Sindia M. https://orca.cardiff.ac.uk/view/cardiffauthors/A185665E.html orcid:0000-0002-4599-5529 orcid:0000-0002-4599-5529 2016. Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition. Geology 44 (12) , pp. 1035-1038. 10.1130/G38636.1 https://doi.org/10.1130/G38636.1 file https://orca.cardiff.ac.uk/95508/1/Geology-2016-Lear-G38636.1.pdf doi:10.1130/G38636.1 cc_by CC-BY QE Geology Article PeerReviewed 2016 ftunivcardiff https://doi.org/10.1130/G38636.1 2022-11-03T23:40:36Z The ~100 k.y. cyclicity of the late Pleistocene ice ages started during the mid-Pleistocene transition (MPT), as ice sheets became larger and persisted for longer. The climate system feedbacks responsible for introducing this nonlinear ice sheet response to orbital variations in insolation remain uncertain. Here we present benthic foraminiferal stable isotope (d18O, d13C) and trace metal records (Cd/Ca, B/Ca, U/Ca) from Deep Sea Drilling Project Site 607 in the North Atlantic. During the onset of the MPT, glacial-interglacial changes in d13C values are associated with changes in nutrient content and carbonate saturation state, consistent with a change in water mass at our site from a nutrient-poor northern source during inter- glacial intervals to a nutrient-rich, corrosive southern source during glacial intervals. The respired carbon content of glacial Atlantic deep water increased across the MPT. Increased dominance of corrosive bottom waters during glacial intervals would have raised mean ocean alkalinity and lowered atmospheric pCO2. The amplitude of glacial-interglacial changes in d13C increased across the MPT, but this was not mirrored by changes in nutrient content. We interpret this in terms of air-sea CO2 exchange effects, which changed the d13C signa- ture of dissolved inorganic carbon in the deep water mass source regions. Increased sea ice cover or ocean strati cation during glacial times may have reduced CO2 outgassing in the Southern Ocean, providing an additional mechanism for reducing glacial atmospheric pCO2. Conversely, following the establishment of the ~100 k.y. glacial cycles, d13C of interglacial northern-sourced waters increased, perhaps re ecting reduced invasion of CO2 into the North Atlantic following the MPT. Article in Journal/Newspaper Ice Sheet North Atlantic Sea ice Southern Ocean Cardiff University: ORCA (Online Research @ Cardiff) Southern Ocean Geology 44 12 1035 1038 |
institution |
Open Polar |
collection |
Cardiff University: ORCA (Online Research @ Cardiff) |
op_collection_id |
ftunivcardiff |
language |
English |
topic |
QE Geology |
spellingShingle |
QE Geology Lear, Caroline H. Billups, Katharina Rickaby, Rosalind E. M. Diester-Haass, Liselotte Mawbey, Elaine M. Sosdian, Sindia M. Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition |
topic_facet |
QE Geology |
description |
The ~100 k.y. cyclicity of the late Pleistocene ice ages started during the mid-Pleistocene transition (MPT), as ice sheets became larger and persisted for longer. The climate system feedbacks responsible for introducing this nonlinear ice sheet response to orbital variations in insolation remain uncertain. Here we present benthic foraminiferal stable isotope (d18O, d13C) and trace metal records (Cd/Ca, B/Ca, U/Ca) from Deep Sea Drilling Project Site 607 in the North Atlantic. During the onset of the MPT, glacial-interglacial changes in d13C values are associated with changes in nutrient content and carbonate saturation state, consistent with a change in water mass at our site from a nutrient-poor northern source during inter- glacial intervals to a nutrient-rich, corrosive southern source during glacial intervals. The respired carbon content of glacial Atlantic deep water increased across the MPT. Increased dominance of corrosive bottom waters during glacial intervals would have raised mean ocean alkalinity and lowered atmospheric pCO2. The amplitude of glacial-interglacial changes in d13C increased across the MPT, but this was not mirrored by changes in nutrient content. We interpret this in terms of air-sea CO2 exchange effects, which changed the d13C signa- ture of dissolved inorganic carbon in the deep water mass source regions. Increased sea ice cover or ocean strati cation during glacial times may have reduced CO2 outgassing in the Southern Ocean, providing an additional mechanism for reducing glacial atmospheric pCO2. Conversely, following the establishment of the ~100 k.y. glacial cycles, d13C of interglacial northern-sourced waters increased, perhaps re ecting reduced invasion of CO2 into the North Atlantic following the MPT. |
format |
Article in Journal/Newspaper |
author |
Lear, Caroline H. Billups, Katharina Rickaby, Rosalind E. M. Diester-Haass, Liselotte Mawbey, Elaine M. Sosdian, Sindia M. |
author_facet |
Lear, Caroline H. Billups, Katharina Rickaby, Rosalind E. M. Diester-Haass, Liselotte Mawbey, Elaine M. Sosdian, Sindia M. |
author_sort |
Lear, Caroline H. |
title |
Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition |
title_short |
Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition |
title_full |
Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition |
title_fullStr |
Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition |
title_full_unstemmed |
Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition |
title_sort |
breathing more deeply: deep ocean carbon storage during the mid-pleistocene climate transition |
publisher |
Geological Society of America |
publishDate |
2016 |
url |
https://orca.cardiff.ac.uk/id/eprint/95508/ https://doi.org/10.1130/G38636.1 https://orca.cardiff.ac.uk/id/eprint/95508/1/Geology-2016-Lear-G38636.1.pdf |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Ice Sheet North Atlantic Sea ice Southern Ocean |
genre_facet |
Ice Sheet North Atlantic Sea ice Southern Ocean |
op_relation |
https://orca.cardiff.ac.uk/id/eprint/95508/1/Geology-2016-Lear-G38636.1.pdf Lear, Caroline H. https://orca.cardiff.ac.uk/view/cardiffauthors/A048848V.html orcid:0000-0002-7533-4430 orcid:0000-0002-7533-4430, Billups, Katharina, Rickaby, Rosalind E. M., Diester-Haass, Liselotte, Mawbey, Elaine M. https://orca.cardiff.ac.uk/view/cardiffauthors/A127259H.html and Sosdian, Sindia M. https://orca.cardiff.ac.uk/view/cardiffauthors/A185665E.html orcid:0000-0002-4599-5529 orcid:0000-0002-4599-5529 2016. Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition. Geology 44 (12) , pp. 1035-1038. 10.1130/G38636.1 https://doi.org/10.1130/G38636.1 file https://orca.cardiff.ac.uk/95508/1/Geology-2016-Lear-G38636.1.pdf doi:10.1130/G38636.1 |
op_rights |
cc_by |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1130/G38636.1 |
container_title |
Geology |
container_volume |
44 |
container_issue |
12 |
container_start_page |
1035 |
op_container_end_page |
1038 |
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1766031820303892480 |