Mid- to late-Holocene oxygen isotopes from Voldafjorden, western Norway
Basin water in deep-silled Norwegian fjords is primarily influenced by inflowing Atlantic water originating from the Norwegian Atlantic Current (NwAC). Previous studies suggest that benthic foraminiferal oxygen isotope records from such fjords are strongly influenced by variability in this current....
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crsagepubl:10.1177/0959683610391318 2023-05-15T17:35:42+02:00 Mid- to late-Holocene oxygen isotopes from Voldafjorden, western Norway Kjennbakken, Heidi Sejrup, Hans Petter Haflidason, Haflidi 2011 http://dx.doi.org/10.1177/0959683610391318 http://journals.sagepub.com/doi/pdf/10.1177/0959683610391318 http://journals.sagepub.com/doi/full-xml/10.1177/0959683610391318 en eng SAGE Publications http://journals.sagepub.com/page/policies/text-and-data-mining-license The Holocene volume 21, issue 6, page 897-909 ISSN 0959-6836 1477-0911 Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change journal-article 2011 crsagepubl https://doi.org/10.1177/0959683610391318 2022-04-14T04:41:44Z Basin water in deep-silled Norwegian fjords is primarily influenced by inflowing Atlantic water originating from the Norwegian Atlantic Current (NwAC). Previous studies suggest that benthic foraminiferal oxygen isotope records from such fjords are strongly influenced by variability in this current. The present paper presents a mid- to late-Holocene record (6–2.2 ka) with 17-yr time resolution from a western Norwegian deep-silled fjord, Voldafjorden. An age model, based on ten AMS radiocarbon dates on marine carbonates and on one plant macrofossil, has been established. The study focuses on the oxygen isotope results, obtained from two species of benthic foraminifera: Cassidulina laevigata and Uvigerina mediterranea. The δ 18 O C. laevigata record has systematically larger amplitudes than the δ 18 O U. mediterranea record, which most likely is related to different life cycles/periods of calcification. The oxygen isotope results show a clear shift towards higher values between 5 and 4 ka, interpreted to reflect a temperature drop in the basin water of c. 1°C. After the temperature drop, the high frequency variability (centennial and multidecadal) changes abruptly towards larger amplitudes. This corresponds to changes in subperiodicity, where a 370 year cycle in the δ 18 O C. laevigata record disappears after 3.8 ka. The δ 18 O transition corresponds to changes in carbon isotopes and grain size distribution, suggesting that a more extensive change in the fjord environment occurred after the cooling. The timing of the oxygen isotope shift towards higher values and the transition in high frequency variability correspond to major changes recorded in paleoclimate archives within the North Atlantic region and globally. Article in Journal/Newspaper North Atlantic SAGE Publications (via Crossref) Norway The Holocene 21 6 897 909 |
institution |
Open Polar |
collection |
SAGE Publications (via Crossref) |
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crsagepubl |
language |
English |
topic |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change |
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Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change Kjennbakken, Heidi Sejrup, Hans Petter Haflidason, Haflidi Mid- to late-Holocene oxygen isotopes from Voldafjorden, western Norway |
topic_facet |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change |
description |
Basin water in deep-silled Norwegian fjords is primarily influenced by inflowing Atlantic water originating from the Norwegian Atlantic Current (NwAC). Previous studies suggest that benthic foraminiferal oxygen isotope records from such fjords are strongly influenced by variability in this current. The present paper presents a mid- to late-Holocene record (6–2.2 ka) with 17-yr time resolution from a western Norwegian deep-silled fjord, Voldafjorden. An age model, based on ten AMS radiocarbon dates on marine carbonates and on one plant macrofossil, has been established. The study focuses on the oxygen isotope results, obtained from two species of benthic foraminifera: Cassidulina laevigata and Uvigerina mediterranea. The δ 18 O C. laevigata record has systematically larger amplitudes than the δ 18 O U. mediterranea record, which most likely is related to different life cycles/periods of calcification. The oxygen isotope results show a clear shift towards higher values between 5 and 4 ka, interpreted to reflect a temperature drop in the basin water of c. 1°C. After the temperature drop, the high frequency variability (centennial and multidecadal) changes abruptly towards larger amplitudes. This corresponds to changes in subperiodicity, where a 370 year cycle in the δ 18 O C. laevigata record disappears after 3.8 ka. The δ 18 O transition corresponds to changes in carbon isotopes and grain size distribution, suggesting that a more extensive change in the fjord environment occurred after the cooling. The timing of the oxygen isotope shift towards higher values and the transition in high frequency variability correspond to major changes recorded in paleoclimate archives within the North Atlantic region and globally. |
format |
Article in Journal/Newspaper |
author |
Kjennbakken, Heidi Sejrup, Hans Petter Haflidason, Haflidi |
author_facet |
Kjennbakken, Heidi Sejrup, Hans Petter Haflidason, Haflidi |
author_sort |
Kjennbakken, Heidi |
title |
Mid- to late-Holocene oxygen isotopes from Voldafjorden, western Norway |
title_short |
Mid- to late-Holocene oxygen isotopes from Voldafjorden, western Norway |
title_full |
Mid- to late-Holocene oxygen isotopes from Voldafjorden, western Norway |
title_fullStr |
Mid- to late-Holocene oxygen isotopes from Voldafjorden, western Norway |
title_full_unstemmed |
Mid- to late-Holocene oxygen isotopes from Voldafjorden, western Norway |
title_sort |
mid- to late-holocene oxygen isotopes from voldafjorden, western norway |
publisher |
SAGE Publications |
publishDate |
2011 |
url |
http://dx.doi.org/10.1177/0959683610391318 http://journals.sagepub.com/doi/pdf/10.1177/0959683610391318 http://journals.sagepub.com/doi/full-xml/10.1177/0959683610391318 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
The Holocene volume 21, issue 6, page 897-909 ISSN 0959-6836 1477-0911 |
op_rights |
http://journals.sagepub.com/page/policies/text-and-data-mining-license |
op_doi |
https://doi.org/10.1177/0959683610391318 |
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The Holocene |
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