Ice-sheet driven weathering input and water mass mixing in the Nordic Seas during the last 25,000 years
Neodymium (Nd) isotopes are a powerful proxy tool for reconstructing past changes in water mass mixing, but reliable application of this proxy requires constraints on past changes of source water compositions. A key region of the global deep water circulation system are the Nordic Seas, which provid...
Published in: | Earth and Planetary Science Letters |
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Online Access: | http://eprints.esc.cam.ac.uk/4744/ http://eprints.esc.cam.ac.uk/4744/1/1-s2.0-S0012821X1930127X-main.pdf http://eprints.esc.cam.ac.uk/4744/2/1-s2.0-S0012821X1930127X-mmc1.xlsx http://eprints.esc.cam.ac.uk/4744/3/1-s2.0-S0012821X1930127X-mmc2.pdf https://doi.org/10.1016/j.epsl.2019.02.030 |
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ftucambridgeesc:oai:eprints.esc.cam.ac.uk:4744 2023-05-15T15:19:06+02:00 Ice-sheet driven weathering input and water mass mixing in the Nordic Seas during the last 25,000 years Struve, T. Roberts, N. L. Frank, M. Piotrowski, A. M. Spielhagen, R. F. Gutjahr, M. Teschner, C. Bauch, H. A. 2019-05 text http://eprints.esc.cam.ac.uk/4744/ http://eprints.esc.cam.ac.uk/4744/1/1-s2.0-S0012821X1930127X-main.pdf http://eprints.esc.cam.ac.uk/4744/2/1-s2.0-S0012821X1930127X-mmc1.xlsx http://eprints.esc.cam.ac.uk/4744/3/1-s2.0-S0012821X1930127X-mmc2.pdf https://doi.org/10.1016/j.epsl.2019.02.030 en eng Elsevier http://eprints.esc.cam.ac.uk/4744/1/1-s2.0-S0012821X1930127X-main.pdf http://eprints.esc.cam.ac.uk/4744/2/1-s2.0-S0012821X1930127X-mmc1.xlsx http://eprints.esc.cam.ac.uk/4744/3/1-s2.0-S0012821X1930127X-mmc2.pdf Struve, T. and Roberts, N. L. and Frank, M. and Piotrowski, A. M. and Spielhagen, R. F. and Gutjahr, M. and Teschner, C. and Bauch, H. A. (2019) Ice-sheet driven weathering input and water mass mixing in the Nordic Seas during the last 25,000 years. Earth and Planetary Science Letters, 514. pp. 108-118. ISSN 0012 821X DOI https://doi.org/10.1016/j.epsl.2019.02.030 <https://doi.org/10.1016/j.epsl.2019.02.030> 01 - Climate Change and Earth-Ocean Atmosphere Systems Article PeerReviewed 2019 ftucambridgeesc https://doi.org/10.1016/j.epsl.2019.02.030 2020-08-27T18:10:05Z Neodymium (Nd) isotopes are a powerful proxy tool for reconstructing past changes in water mass mixing, but reliable application of this proxy requires constraints on past changes of source water compositions. A key region of the global deep water circulation system are the Nordic Seas, which provide dense waters fundamental for the formation of North Atlantic Deep Water (NADW). Yet, the Nd isotope evolution of past deep waters in the Nordic Seas is so far poorly constrained. Here we present the first reconstructions of seawater Nd isotope compositions extracted from marine sediments at two locations in the central and northern Nordic Seas covering the period from the last glacial to the present. Further insights into past changes in sediment provenance, weathering inputs and water mass mixing are provided by complementary seawater and detrital strontium (Sr) and lead (Pb) isotope compositions. Our new data reveal that changes in source and magnitude of weathering inputs from the Scandinavian and Svalbard–Barents Ice Sheets (SIS and SBIS, respectively) controlled the Nd and Pb isotope composition of the Nordic Seas’ deep waters during the last glacial period. During the Last Glacial Maximum (LGM), deep waters showed distinctly unradiogenic Nd and radiogenic Pb isotope signatures most likely driven by weathering inputs of the SBIS. In contrast, the deglaciation was characterized by enhanced SBIS ice dynamics and/or meltwater release delivering sediments from the distal Eurasian shelves to the Norwegian Sea. Pulses of volcanogenic sediment supply changed the deep water Nd isotope composition during Heinrich Stadials 1, 2 and the Bølling period. As such, the glacial–deglacial Nd and Pb isotope evolution was markedly different in the Nordic Seas, the North Atlantic and the Arctic Oceans, respectively. During the Holocene, Pb isotopes indicate synchronized weathering fluxes around the North Atlantic, whereas the influence of local weathering input on the Nd isotope evolution of the deep Nordic Seas ceased. Instead, the Holocene Nd isotope signal has been driven by the strength of the advection/convection of water masses in the study area. These new constraints on changes in the Nordic Seas provide important endmember information for Nd isotope based reconstructions of NADW export downstream in the Atlantic Ocean. Article in Journal/Newspaper Arctic Climate change Ice Sheet NADW Nordic Seas North Atlantic Deep Water North Atlantic Norwegian Sea Svalbard University of Cambridge, Department of Earth Sciences: ESC Publications Arctic Norwegian Sea Svalbard Earth and Planetary Science Letters 514 108 118 |
institution |
Open Polar |
collection |
University of Cambridge, Department of Earth Sciences: ESC Publications |
op_collection_id |
ftucambridgeesc |
language |
English |
topic |
01 - Climate Change and Earth-Ocean Atmosphere Systems |
spellingShingle |
01 - Climate Change and Earth-Ocean Atmosphere Systems Struve, T. Roberts, N. L. Frank, M. Piotrowski, A. M. Spielhagen, R. F. Gutjahr, M. Teschner, C. Bauch, H. A. Ice-sheet driven weathering input and water mass mixing in the Nordic Seas during the last 25,000 years |
topic_facet |
01 - Climate Change and Earth-Ocean Atmosphere Systems |
description |
Neodymium (Nd) isotopes are a powerful proxy tool for reconstructing past changes in water mass mixing, but reliable application of this proxy requires constraints on past changes of source water compositions. A key region of the global deep water circulation system are the Nordic Seas, which provide dense waters fundamental for the formation of North Atlantic Deep Water (NADW). Yet, the Nd isotope evolution of past deep waters in the Nordic Seas is so far poorly constrained. Here we present the first reconstructions of seawater Nd isotope compositions extracted from marine sediments at two locations in the central and northern Nordic Seas covering the period from the last glacial to the present. Further insights into past changes in sediment provenance, weathering inputs and water mass mixing are provided by complementary seawater and detrital strontium (Sr) and lead (Pb) isotope compositions. Our new data reveal that changes in source and magnitude of weathering inputs from the Scandinavian and Svalbard–Barents Ice Sheets (SIS and SBIS, respectively) controlled the Nd and Pb isotope composition of the Nordic Seas’ deep waters during the last glacial period. During the Last Glacial Maximum (LGM), deep waters showed distinctly unradiogenic Nd and radiogenic Pb isotope signatures most likely driven by weathering inputs of the SBIS. In contrast, the deglaciation was characterized by enhanced SBIS ice dynamics and/or meltwater release delivering sediments from the distal Eurasian shelves to the Norwegian Sea. Pulses of volcanogenic sediment supply changed the deep water Nd isotope composition during Heinrich Stadials 1, 2 and the Bølling period. As such, the glacial–deglacial Nd and Pb isotope evolution was markedly different in the Nordic Seas, the North Atlantic and the Arctic Oceans, respectively. During the Holocene, Pb isotopes indicate synchronized weathering fluxes around the North Atlantic, whereas the influence of local weathering input on the Nd isotope evolution of the deep Nordic Seas ceased. Instead, the Holocene Nd isotope signal has been driven by the strength of the advection/convection of water masses in the study area. These new constraints on changes in the Nordic Seas provide important endmember information for Nd isotope based reconstructions of NADW export downstream in the Atlantic Ocean. |
format |
Article in Journal/Newspaper |
author |
Struve, T. Roberts, N. L. Frank, M. Piotrowski, A. M. Spielhagen, R. F. Gutjahr, M. Teschner, C. Bauch, H. A. |
author_facet |
Struve, T. Roberts, N. L. Frank, M. Piotrowski, A. M. Spielhagen, R. F. Gutjahr, M. Teschner, C. Bauch, H. A. |
author_sort |
Struve, T. |
title |
Ice-sheet driven weathering input and water mass mixing in the Nordic Seas during the last 25,000 years |
title_short |
Ice-sheet driven weathering input and water mass mixing in the Nordic Seas during the last 25,000 years |
title_full |
Ice-sheet driven weathering input and water mass mixing in the Nordic Seas during the last 25,000 years |
title_fullStr |
Ice-sheet driven weathering input and water mass mixing in the Nordic Seas during the last 25,000 years |
title_full_unstemmed |
Ice-sheet driven weathering input and water mass mixing in the Nordic Seas during the last 25,000 years |
title_sort |
ice-sheet driven weathering input and water mass mixing in the nordic seas during the last 25,000 years |
publisher |
Elsevier |
publishDate |
2019 |
url |
http://eprints.esc.cam.ac.uk/4744/ http://eprints.esc.cam.ac.uk/4744/1/1-s2.0-S0012821X1930127X-main.pdf http://eprints.esc.cam.ac.uk/4744/2/1-s2.0-S0012821X1930127X-mmc1.xlsx http://eprints.esc.cam.ac.uk/4744/3/1-s2.0-S0012821X1930127X-mmc2.pdf https://doi.org/10.1016/j.epsl.2019.02.030 |
geographic |
Arctic Norwegian Sea Svalbard |
geographic_facet |
Arctic Norwegian Sea Svalbard |
genre |
Arctic Climate change Ice Sheet NADW Nordic Seas North Atlantic Deep Water North Atlantic Norwegian Sea Svalbard |
genre_facet |
Arctic Climate change Ice Sheet NADW Nordic Seas North Atlantic Deep Water North Atlantic Norwegian Sea Svalbard |
op_relation |
http://eprints.esc.cam.ac.uk/4744/1/1-s2.0-S0012821X1930127X-main.pdf http://eprints.esc.cam.ac.uk/4744/2/1-s2.0-S0012821X1930127X-mmc1.xlsx http://eprints.esc.cam.ac.uk/4744/3/1-s2.0-S0012821X1930127X-mmc2.pdf Struve, T. and Roberts, N. L. and Frank, M. and Piotrowski, A. M. and Spielhagen, R. F. and Gutjahr, M. and Teschner, C. and Bauch, H. A. (2019) Ice-sheet driven weathering input and water mass mixing in the Nordic Seas during the last 25,000 years. Earth and Planetary Science Letters, 514. pp. 108-118. ISSN 0012 821X DOI https://doi.org/10.1016/j.epsl.2019.02.030 <https://doi.org/10.1016/j.epsl.2019.02.030> |
op_doi |
https://doi.org/10.1016/j.epsl.2019.02.030 |
container_title |
Earth and Planetary Science Letters |
container_volume |
514 |
container_start_page |
108 |
op_container_end_page |
118 |
_version_ |
1766349293746126848 |