Glacial-to-deglacial changes in North Atlantic meltwater advection and deep-water formation – Centennial-to-millennial-scale 14 C records from the Azores plateau
The last deglacial was marked by tremendous changes in ocean temperature and circulation as well as atmospheric CO2 and 14C. We employed the “14C plateau-tuning technique” to a centennial-scale planktic 14C record of core MD08-3180 retrieved S.W. of the Azores Islands at ∼3060 m water depth to estab...
Published in: | Geochimica et Cosmochimica Acta |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2018
|
Subjects: | |
Online Access: | https://oceanrep.geomar.de/id/eprint/43927/ https://oceanrep.geomar.de/id/eprint/43927/1/Balmer.pdf https://doi.org/10.1016/j.gca.2018.03.001 |
id |
ftoceanrep:oai:oceanrep.geomar.de:43927 |
---|---|
record_format |
openpolar |
spelling |
ftoceanrep:oai:oceanrep.geomar.de:43927 2023-05-15T16:51:54+02:00 Glacial-to-deglacial changes in North Atlantic meltwater advection and deep-water formation – Centennial-to-millennial-scale 14 C records from the Azores plateau Balmer, Sven Sarnthein, Michael 2018 text https://oceanrep.geomar.de/id/eprint/43927/ https://oceanrep.geomar.de/id/eprint/43927/1/Balmer.pdf https://doi.org/10.1016/j.gca.2018.03.001 en eng Elsevier https://oceanrep.geomar.de/id/eprint/43927/1/Balmer.pdf Balmer, S. and Sarnthein, M. (2018) Glacial-to-deglacial changes in North Atlantic meltwater advection and deep-water formation – Centennial-to-millennial-scale 14 C records from the Azores plateau. Geochimica et Cosmochimica Acta, 236 . pp. 399-415. DOI 10.1016/j.gca.2018.03.001 <https://doi.org/10.1016/j.gca.2018.03.001>. doi:10.1016/j.gca.2018.03.001 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2018 ftoceanrep https://doi.org/10.1016/j.gca.2018.03.001 2023-04-07T15:40:50Z The last deglacial was marked by tremendous changes in ocean temperature and circulation as well as atmospheric CO2 and 14C. We employed the “14C plateau-tuning technique” to a centennial-scale planktic 14C record of core MD08-3180 retrieved S.W. of the Azores Islands at ∼3060 m water depth to establish both a new standard of absolute age control and a record of past 14C reservoir ages of ocean surface waters. Both δ18O minima of G. bulloides and high planktic reservoir ages of ∼1600 to 2170 yr suggest two major melt water incursions that reached from the Labrador Sea up to the subtropics over Heinrich Stadial 1 (HS-1). In parallel, we established a record of (apparent) benthic ventilation ages that add the planktic 14C reservoir ages together with the benthic-planktic 14C age difference at the site and time of deposition, a sum finally adjusted to past changes in atmospheric 14C that occurred since the time of deep-water formation. Near the Azores apparent deep-water ages of the Last Glacial Maximum were as low as 340–740 yr, which suggests a lateral advection of young North Atlantic Deep Waters (NADW) from subpolar regions south of Iceland, in harmony with recent model simulation and in contrast to a widely assumed major shoaling of glacial deep-water formation. During HS-1, local benthic ventilation ages increased up to 2200–2550 yr, thus suggest an incursion of old southern-source deep waters, an unstable regime that was interrupted by brief pulses of NADW incursion near 16, 15.6 cal. ka, and most salient, near 14.9/14.7 ka. Article in Journal/Newspaper Iceland Labrador Sea NADW North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Geochimica et Cosmochimica Acta 236 399 415 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
The last deglacial was marked by tremendous changes in ocean temperature and circulation as well as atmospheric CO2 and 14C. We employed the “14C plateau-tuning technique” to a centennial-scale planktic 14C record of core MD08-3180 retrieved S.W. of the Azores Islands at ∼3060 m water depth to establish both a new standard of absolute age control and a record of past 14C reservoir ages of ocean surface waters. Both δ18O minima of G. bulloides and high planktic reservoir ages of ∼1600 to 2170 yr suggest two major melt water incursions that reached from the Labrador Sea up to the subtropics over Heinrich Stadial 1 (HS-1). In parallel, we established a record of (apparent) benthic ventilation ages that add the planktic 14C reservoir ages together with the benthic-planktic 14C age difference at the site and time of deposition, a sum finally adjusted to past changes in atmospheric 14C that occurred since the time of deep-water formation. Near the Azores apparent deep-water ages of the Last Glacial Maximum were as low as 340–740 yr, which suggests a lateral advection of young North Atlantic Deep Waters (NADW) from subpolar regions south of Iceland, in harmony with recent model simulation and in contrast to a widely assumed major shoaling of glacial deep-water formation. During HS-1, local benthic ventilation ages increased up to 2200–2550 yr, thus suggest an incursion of old southern-source deep waters, an unstable regime that was interrupted by brief pulses of NADW incursion near 16, 15.6 cal. ka, and most salient, near 14.9/14.7 ka. |
format |
Article in Journal/Newspaper |
author |
Balmer, Sven Sarnthein, Michael |
spellingShingle |
Balmer, Sven Sarnthein, Michael Glacial-to-deglacial changes in North Atlantic meltwater advection and deep-water formation – Centennial-to-millennial-scale 14 C records from the Azores plateau |
author_facet |
Balmer, Sven Sarnthein, Michael |
author_sort |
Balmer, Sven |
title |
Glacial-to-deglacial changes in North Atlantic meltwater advection and deep-water formation – Centennial-to-millennial-scale 14 C records from the Azores plateau |
title_short |
Glacial-to-deglacial changes in North Atlantic meltwater advection and deep-water formation – Centennial-to-millennial-scale 14 C records from the Azores plateau |
title_full |
Glacial-to-deglacial changes in North Atlantic meltwater advection and deep-water formation – Centennial-to-millennial-scale 14 C records from the Azores plateau |
title_fullStr |
Glacial-to-deglacial changes in North Atlantic meltwater advection and deep-water formation – Centennial-to-millennial-scale 14 C records from the Azores plateau |
title_full_unstemmed |
Glacial-to-deglacial changes in North Atlantic meltwater advection and deep-water formation – Centennial-to-millennial-scale 14 C records from the Azores plateau |
title_sort |
glacial-to-deglacial changes in north atlantic meltwater advection and deep-water formation – centennial-to-millennial-scale 14 c records from the azores plateau |
publisher |
Elsevier |
publishDate |
2018 |
url |
https://oceanrep.geomar.de/id/eprint/43927/ https://oceanrep.geomar.de/id/eprint/43927/1/Balmer.pdf https://doi.org/10.1016/j.gca.2018.03.001 |
genre |
Iceland Labrador Sea NADW North Atlantic |
genre_facet |
Iceland Labrador Sea NADW North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/43927/1/Balmer.pdf Balmer, S. and Sarnthein, M. (2018) Glacial-to-deglacial changes in North Atlantic meltwater advection and deep-water formation – Centennial-to-millennial-scale 14 C records from the Azores plateau. Geochimica et Cosmochimica Acta, 236 . pp. 399-415. DOI 10.1016/j.gca.2018.03.001 <https://doi.org/10.1016/j.gca.2018.03.001>. doi:10.1016/j.gca.2018.03.001 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.gca.2018.03.001 |
container_title |
Geochimica et Cosmochimica Acta |
container_volume |
236 |
container_start_page |
399 |
op_container_end_page |
415 |
_version_ |
1766042022371655680 |