Subsurface North Atlantic warming as a trigger of rapid cooling events: evidence from the early Pleistocene (MIS 31–19)
Subsurface water column dynamics in the subpolar North Atlantic were reconstructed in order to improve the understanding of the cause of abrupt ice-rafted detritus (IRD) events during cold periods of the early Pleistocene. We used paired Mg / Ca and δ 18 O measurements of Neogloboquadrina pachyderma...
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ftdoajarticles:oai:doaj.org/article:a291dcf2661b45beb6e10b4fdd50c21b 2023-05-15T16:41:59+02:00 Subsurface North Atlantic warming as a trigger of rapid cooling events: evidence from the early Pleistocene (MIS 31–19) I. Hernández-Almeida F.-J. Sierro I. Cacho J.-A. Flores 2015-04-01T00:00:00Z https://doi.org/10.5194/cp-11-687-2015 https://doaj.org/article/a291dcf2661b45beb6e10b4fdd50c21b EN eng Copernicus Publications http://www.clim-past.net/11/687/2015/cp-11-687-2015.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 1814-9324 1814-9332 doi:10.5194/cp-11-687-2015 https://doaj.org/article/a291dcf2661b45beb6e10b4fdd50c21b Climate of the Past, Vol 11, Iss 4, Pp 687-696 (2015) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2015 ftdoajarticles https://doi.org/10.5194/cp-11-687-2015 2022-12-30T23:37:24Z Subsurface water column dynamics in the subpolar North Atlantic were reconstructed in order to improve the understanding of the cause of abrupt ice-rafted detritus (IRD) events during cold periods of the early Pleistocene. We used paired Mg / Ca and δ 18 O measurements of Neogloboquadrina pachyderma (sinistral – sin.), deep-dwelling planktonic foraminifera, to estimate the subsurface temperatures and seawater δ 18 O from a sediment core from Gardar Drift, in the subpolar North Atlantic. Carbon isotopes of benthic and planktonic foraminifera from the same site provide information about the ventilation and water column nutrient gradient. Mg / Ca-based temperatures and seawater δ 18 O suggest increased subsurface temperatures and salinities during ice-rafting, likely due to northward subsurface transport of subtropical waters during periods of weaker Atlantic Meridional Overturning Circulation (AMOC). Planktonic carbon isotopes support this suggestion, showing coincident increased subsurface ventilation during deposition of IRD. Subsurface accumulation of warm waters would have resulted in basal warming and break-up of ice-shelves, leading to massive iceberg discharges in the North Atlantic. The release of heat stored at the subsurface to the atmosphere would have helped to restart the AMOC. This mechanism is in agreement with modelling and proxy studies that observe a subsurface warming in the North Atlantic in response to AMOC slowdown during Marine Isotope Stage (MIS) 3. Article in Journal/Newspaper Ice Shelves Neogloboquadrina pachyderma North Atlantic Planktonic foraminifera Directory of Open Access Journals: DOAJ Articles Climate of the Past 11 4 687 696 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
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Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 I. Hernández-Almeida F.-J. Sierro I. Cacho J.-A. Flores Subsurface North Atlantic warming as a trigger of rapid cooling events: evidence from the early Pleistocene (MIS 31–19) |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
Subsurface water column dynamics in the subpolar North Atlantic were reconstructed in order to improve the understanding of the cause of abrupt ice-rafted detritus (IRD) events during cold periods of the early Pleistocene. We used paired Mg / Ca and δ 18 O measurements of Neogloboquadrina pachyderma (sinistral – sin.), deep-dwelling planktonic foraminifera, to estimate the subsurface temperatures and seawater δ 18 O from a sediment core from Gardar Drift, in the subpolar North Atlantic. Carbon isotopes of benthic and planktonic foraminifera from the same site provide information about the ventilation and water column nutrient gradient. Mg / Ca-based temperatures and seawater δ 18 O suggest increased subsurface temperatures and salinities during ice-rafting, likely due to northward subsurface transport of subtropical waters during periods of weaker Atlantic Meridional Overturning Circulation (AMOC). Planktonic carbon isotopes support this suggestion, showing coincident increased subsurface ventilation during deposition of IRD. Subsurface accumulation of warm waters would have resulted in basal warming and break-up of ice-shelves, leading to massive iceberg discharges in the North Atlantic. The release of heat stored at the subsurface to the atmosphere would have helped to restart the AMOC. This mechanism is in agreement with modelling and proxy studies that observe a subsurface warming in the North Atlantic in response to AMOC slowdown during Marine Isotope Stage (MIS) 3. |
format |
Article in Journal/Newspaper |
author |
I. Hernández-Almeida F.-J. Sierro I. Cacho J.-A. Flores |
author_facet |
I. Hernández-Almeida F.-J. Sierro I. Cacho J.-A. Flores |
author_sort |
I. Hernández-Almeida |
title |
Subsurface North Atlantic warming as a trigger of rapid cooling events: evidence from the early Pleistocene (MIS 31–19) |
title_short |
Subsurface North Atlantic warming as a trigger of rapid cooling events: evidence from the early Pleistocene (MIS 31–19) |
title_full |
Subsurface North Atlantic warming as a trigger of rapid cooling events: evidence from the early Pleistocene (MIS 31–19) |
title_fullStr |
Subsurface North Atlantic warming as a trigger of rapid cooling events: evidence from the early Pleistocene (MIS 31–19) |
title_full_unstemmed |
Subsurface North Atlantic warming as a trigger of rapid cooling events: evidence from the early Pleistocene (MIS 31–19) |
title_sort |
subsurface north atlantic warming as a trigger of rapid cooling events: evidence from the early pleistocene (mis 31–19) |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/cp-11-687-2015 https://doaj.org/article/a291dcf2661b45beb6e10b4fdd50c21b |
genre |
Ice Shelves Neogloboquadrina pachyderma North Atlantic Planktonic foraminifera |
genre_facet |
Ice Shelves Neogloboquadrina pachyderma North Atlantic Planktonic foraminifera |
op_source |
Climate of the Past, Vol 11, Iss 4, Pp 687-696 (2015) |
op_relation |
http://www.clim-past.net/11/687/2015/cp-11-687-2015.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 1814-9324 1814-9332 doi:10.5194/cp-11-687-2015 https://doaj.org/article/a291dcf2661b45beb6e10b4fdd50c21b |
op_doi |
https://doi.org/10.5194/cp-11-687-2015 |
container_title |
Climate of the Past |
container_volume |
11 |
container_issue |
4 |
container_start_page |
687 |
op_container_end_page |
696 |
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1766032457046425600 |