Benthic foraminifera indicate Glacial North Pacific Intermediate Water and reduced primary productivity over Bowers Ridge, Bering Sea, since the Mid-Brunhes Transition
The Mid-Brunhes Transition (MBT) saw an increase in the amplitude of glacial cycles expressed in ice core and deep ocean records from about 400 ka, but its influence on high-latitude climates is not fully understood. The Arctic Ocean is thought to have warmed and exhibited reduced sea ice, but littl...
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2019
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Online Access: | https://doi.org/10.5194/jm-38-177-2019 https://doaj.org/article/8c1288e21ef64f2fb56635ba1c125494 |
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ftdoajarticles:oai:doaj.org/article:8c1288e21ef64f2fb56635ba1c125494 2023-05-15T15:02:07+02:00 Benthic foraminifera indicate Glacial North Pacific Intermediate Water and reduced primary productivity over Bowers Ridge, Bering Sea, since the Mid-Brunhes Transition S. Kender A. Aturamu J. Zalasiewicz M. A. Kaminski M. Williams 2019-12-01T00:00:00Z https://doi.org/10.5194/jm-38-177-2019 https://doaj.org/article/8c1288e21ef64f2fb56635ba1c125494 EN eng Copernicus Publications https://www.j-micropalaeontol.net/38/177/2019/jm-38-177-2019.pdf https://doaj.org/toc/0262-821X https://doaj.org/toc/2041-4978 doi:10.5194/jm-38-177-2019 0262-821X 2041-4978 https://doaj.org/article/8c1288e21ef64f2fb56635ba1c125494 Journal of Micropalaeontology, Vol 38, Pp 177-187 (2019) Geology QE1-996.5 article 2019 ftdoajarticles https://doi.org/10.5194/jm-38-177-2019 2022-12-30T20:47:11Z The Mid-Brunhes Transition (MBT) saw an increase in the amplitude of glacial cycles expressed in ice core and deep ocean records from about 400 ka, but its influence on high-latitude climates is not fully understood. The Arctic Ocean is thought to have warmed and exhibited reduced sea ice, but little is known of sea ice marginal locations such as the Bering Sea. The Bering Sea is the link between the Arctic and Pacific Ocean and is an area of high productivity and CO 2 ventilation; it hosts a pronounced oxygen minimum zone (OMZ) and is thought to be the location of Glacial North Pacific Intermediate Water (GNPIW) formation in the Pleistocene. To understand palaeoceanographic change in the region, we analysed benthic foraminiferal faunas from Bowers Ridge (Site U1342, 800 m of water depth) over the past 600 kyr, as they are uniquely well preserved and sensitive to changes in deep and surface ocean conditions. We identified and imaged 71 taxa and provide a full taxonomy. Foraminiferal preservation is markedly higher during glacials, indicating the presence of less corrosive GNPIW. The most abundant species are Bulimina exilis , Takayanagia delicata , Alabaminella weddellensis , Gyroidina sp. 2, Cassidulina laevigata , Islandiella norcrossi , and Uvigerina bifurcata , consistent with broadly high net primary production throughout the last 600 kyr. Correspondence analysis shows that the most significant Assemblage 1 comprises B. exilis , T. delicata , Bolivina spissa , and Brizalina , which occur sporadically within intervals of laminated, biogenic-rich sediment, mostly during glacials and also some deglacials, and are interpreted as indicating very high productivity. Other assemblages contain the phytodetritivore species A. weddellensis , I. norcrossi , and C. laevigata , indicative of seasonal phytoplankton blooms. Before the MBT, more numerous intervals of the very high-productivity Assemblage 1 and A. weddellensis occur, which we suggest reflect a time of more sea-ice-related seasonal stratification and ice edge ... Article in Journal/Newspaper Arctic Arctic Ocean Bering Sea Foraminifera* ice core Phytoplankton Sea ice Directory of Open Access Journals: DOAJ Articles Arctic Arctic Ocean Bering Sea Pacific Bowers ENVELOPE(164.083,164.083,-85.000,-85.000) Journal of Micropalaeontology 38 2 177 187 |
institution |
Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 |
spellingShingle |
Geology QE1-996.5 S. Kender A. Aturamu J. Zalasiewicz M. A. Kaminski M. Williams Benthic foraminifera indicate Glacial North Pacific Intermediate Water and reduced primary productivity over Bowers Ridge, Bering Sea, since the Mid-Brunhes Transition |
topic_facet |
Geology QE1-996.5 |
description |
The Mid-Brunhes Transition (MBT) saw an increase in the amplitude of glacial cycles expressed in ice core and deep ocean records from about 400 ka, but its influence on high-latitude climates is not fully understood. The Arctic Ocean is thought to have warmed and exhibited reduced sea ice, but little is known of sea ice marginal locations such as the Bering Sea. The Bering Sea is the link between the Arctic and Pacific Ocean and is an area of high productivity and CO 2 ventilation; it hosts a pronounced oxygen minimum zone (OMZ) and is thought to be the location of Glacial North Pacific Intermediate Water (GNPIW) formation in the Pleistocene. To understand palaeoceanographic change in the region, we analysed benthic foraminiferal faunas from Bowers Ridge (Site U1342, 800 m of water depth) over the past 600 kyr, as they are uniquely well preserved and sensitive to changes in deep and surface ocean conditions. We identified and imaged 71 taxa and provide a full taxonomy. Foraminiferal preservation is markedly higher during glacials, indicating the presence of less corrosive GNPIW. The most abundant species are Bulimina exilis , Takayanagia delicata , Alabaminella weddellensis , Gyroidina sp. 2, Cassidulina laevigata , Islandiella norcrossi , and Uvigerina bifurcata , consistent with broadly high net primary production throughout the last 600 kyr. Correspondence analysis shows that the most significant Assemblage 1 comprises B. exilis , T. delicata , Bolivina spissa , and Brizalina , which occur sporadically within intervals of laminated, biogenic-rich sediment, mostly during glacials and also some deglacials, and are interpreted as indicating very high productivity. Other assemblages contain the phytodetritivore species A. weddellensis , I. norcrossi , and C. laevigata , indicative of seasonal phytoplankton blooms. Before the MBT, more numerous intervals of the very high-productivity Assemblage 1 and A. weddellensis occur, which we suggest reflect a time of more sea-ice-related seasonal stratification and ice edge ... |
format |
Article in Journal/Newspaper |
author |
S. Kender A. Aturamu J. Zalasiewicz M. A. Kaminski M. Williams |
author_facet |
S. Kender A. Aturamu J. Zalasiewicz M. A. Kaminski M. Williams |
author_sort |
S. Kender |
title |
Benthic foraminifera indicate Glacial North Pacific Intermediate Water and reduced primary productivity over Bowers Ridge, Bering Sea, since the Mid-Brunhes Transition |
title_short |
Benthic foraminifera indicate Glacial North Pacific Intermediate Water and reduced primary productivity over Bowers Ridge, Bering Sea, since the Mid-Brunhes Transition |
title_full |
Benthic foraminifera indicate Glacial North Pacific Intermediate Water and reduced primary productivity over Bowers Ridge, Bering Sea, since the Mid-Brunhes Transition |
title_fullStr |
Benthic foraminifera indicate Glacial North Pacific Intermediate Water and reduced primary productivity over Bowers Ridge, Bering Sea, since the Mid-Brunhes Transition |
title_full_unstemmed |
Benthic foraminifera indicate Glacial North Pacific Intermediate Water and reduced primary productivity over Bowers Ridge, Bering Sea, since the Mid-Brunhes Transition |
title_sort |
benthic foraminifera indicate glacial north pacific intermediate water and reduced primary productivity over bowers ridge, bering sea, since the mid-brunhes transition |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/jm-38-177-2019 https://doaj.org/article/8c1288e21ef64f2fb56635ba1c125494 |
long_lat |
ENVELOPE(164.083,164.083,-85.000,-85.000) |
geographic |
Arctic Arctic Ocean Bering Sea Pacific Bowers |
geographic_facet |
Arctic Arctic Ocean Bering Sea Pacific Bowers |
genre |
Arctic Arctic Ocean Bering Sea Foraminifera* ice core Phytoplankton Sea ice |
genre_facet |
Arctic Arctic Ocean Bering Sea Foraminifera* ice core Phytoplankton Sea ice |
op_source |
Journal of Micropalaeontology, Vol 38, Pp 177-187 (2019) |
op_relation |
https://www.j-micropalaeontol.net/38/177/2019/jm-38-177-2019.pdf https://doaj.org/toc/0262-821X https://doaj.org/toc/2041-4978 doi:10.5194/jm-38-177-2019 0262-821X 2041-4978 https://doaj.org/article/8c1288e21ef64f2fb56635ba1c125494 |
op_doi |
https://doi.org/10.5194/jm-38-177-2019 |
container_title |
Journal of Micropalaeontology |
container_volume |
38 |
container_issue |
2 |
container_start_page |
177 |
op_container_end_page |
187 |
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1766334100230111232 |