Multi-proxy record of ocean-climate variability during the last two millennia on the Mackenzie Shelf, Beaufort Sea
A 2,000 year-long oceanographic history, in sub-centennial resolution, from a Canadian Beaufort Sea continental shelf site (60 meters water depth) near the Mackenzie River outlet is reconstructed from ostracode and foraminifera faunal assemblages, shell stable isotopes (δ 18 O, δ 13 C) and sediment...
Published in: | Micropaleontology |
---|---|
Main Authors: | , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2023
|
Subjects: | |
Online Access: | https://pure.au.dk/portal/da/publications/multiproxy-record-of-oceanclimate-variability-during-the-last-two-millennia-on-the-mackenzie-shelf-beaufort-sea(18c53b63-e92c-4cf2-b445-fcacb58c48e7).html https://doi.org/10.47894/mpal.69.3.04 http://www.scopus.com/inward/record.url?scp=85145750718&partnerID=8YFLogxK |
id |
ftuniaarhuspubl:oai:pure.atira.dk:publications/18c53b63-e92c-4cf2-b445-fcacb58c48e7 |
---|---|
record_format |
openpolar |
spelling |
ftuniaarhuspubl:oai:pure.atira.dk:publications/18c53b63-e92c-4cf2-b445-fcacb58c48e7 2023-12-31T10:04:21+01:00 Multi-proxy record of ocean-climate variability during the last two millennia on the Mackenzie Shelf, Beaufort Sea Gemery, Laura Cronin, Thomas M. Cooper, Lee W. Roberts, Lucy R. Keigwin, Lloyd D. Addison, Jason A. Leng, Melanie J. Lin, Peigen Magen, Cédric Marot, Marci E. Schwartz, Valerie 2023-05 https://pure.au.dk/portal/da/publications/multiproxy-record-of-oceanclimate-variability-during-the-last-two-millennia-on-the-mackenzie-shelf-beaufort-sea(18c53b63-e92c-4cf2-b445-fcacb58c48e7).html https://doi.org/10.47894/mpal.69.3.04 http://www.scopus.com/inward/record.url?scp=85145750718&partnerID=8YFLogxK eng eng https://pure.au.dk/portal/da/publications/multiproxy-record-of-oceanclimate-variability-during-the-last-two-millennia-on-the-mackenzie-shelf-beaufort-sea(18c53b63-e92c-4cf2-b445-fcacb58c48e7).html info:eu-repo/semantics/restrictedAccess Gemery , L , Cronin , T M , Cooper , L W , Roberts , L R , Keigwin , L D , Addison , J A , Leng , M J , Lin , P , Magen , C , Marot , M E & Schwartz , V 2023 , ' Multi-proxy record of ocean-climate variability during the last two millennia on the Mackenzie Shelf, Beaufort Sea ' , Micropaleontology , vol. 69 , no. 3 , pp. 345-366 . https://doi.org/10.47894/mpal.69.3.04 Arctic Ocean benthic foraminifera benthic ostracodes biogenic silica late Holocene microfossils paleoceanography stable isotopes article 2023 ftuniaarhuspubl https://doi.org/10.47894/mpal.69.3.04 2023-12-07T00:06:40Z A 2,000 year-long oceanographic history, in sub-centennial resolution, from a Canadian Beaufort Sea continental shelf site (60 meters water depth) near the Mackenzie River outlet is reconstructed from ostracode and foraminifera faunal assemblages, shell stable isotopes (δ 18 O, δ 13 C) and sediment biogenic silica. The chronology of three sediment cores making up the composite section was established using 137 Cs and 210 Pb dating for the most recent 150 years and combined with linear interpolation of radiocarbon dates from bivalve shells and foraminifera tests. Continuous centimeter-sampling of the multicore and high-resolution sampling of a gravity and piston core yielded a time-averaged faunal record of every ~40 years from 0 to 1850 CE and every ~24 years from 1850 to 2013 CE. Proxy records were consistent with temperature oscillations and related changes in organic carbon cycling associated with the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA). Abundance changes in dominant microfossil species, such as the ostracode Paracyprideis pseudopunctillata and agglutinated foraminifers Spiroplectammina biformis and S. earlandi, are used as indicators of less saline, and possibly corrosive/turbid bottom conditions associated with the MCA (~800-1200 CE) and the most recent ~60 years (1950-2013). During these periods, pronounced fluctuations in these species suggest that prolonged seasonal sea-ice melting, changes in riverine inputs and sediment dynamics affected the benthic environment. Taxa analyzed for stable oxygen isotope composition of carbonates show the lowest δ 18 O values during intervals within the MCA and the highest during the late LIA, which is consistent with a 1° to 2°C cooling of bottom waters. Faunal and isotopic changes during the cooler LIA (1300-1850 CE) are most apparent at ~1500-1850 CE and are particularly pronounced during 1850 to ~1900 CE, with a ~0.5 per mil increase in δ 18 O values of carbonates from median values in the analyzed taxa. This very cold 50-year period suggests ... Article in Journal/Newspaper Arctic Arctic Ocean Beaufort Sea Foraminifera* Mackenzie river Mackenzie Shelf Sea ice Aarhus University: Research Micropaleontology 69 3 345 360 |
institution |
Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
topic |
Arctic Ocean benthic foraminifera benthic ostracodes biogenic silica late Holocene microfossils paleoceanography stable isotopes |
spellingShingle |
Arctic Ocean benthic foraminifera benthic ostracodes biogenic silica late Holocene microfossils paleoceanography stable isotopes Gemery, Laura Cronin, Thomas M. Cooper, Lee W. Roberts, Lucy R. Keigwin, Lloyd D. Addison, Jason A. Leng, Melanie J. Lin, Peigen Magen, Cédric Marot, Marci E. Schwartz, Valerie Multi-proxy record of ocean-climate variability during the last two millennia on the Mackenzie Shelf, Beaufort Sea |
topic_facet |
Arctic Ocean benthic foraminifera benthic ostracodes biogenic silica late Holocene microfossils paleoceanography stable isotopes |
description |
A 2,000 year-long oceanographic history, in sub-centennial resolution, from a Canadian Beaufort Sea continental shelf site (60 meters water depth) near the Mackenzie River outlet is reconstructed from ostracode and foraminifera faunal assemblages, shell stable isotopes (δ 18 O, δ 13 C) and sediment biogenic silica. The chronology of three sediment cores making up the composite section was established using 137 Cs and 210 Pb dating for the most recent 150 years and combined with linear interpolation of radiocarbon dates from bivalve shells and foraminifera tests. Continuous centimeter-sampling of the multicore and high-resolution sampling of a gravity and piston core yielded a time-averaged faunal record of every ~40 years from 0 to 1850 CE and every ~24 years from 1850 to 2013 CE. Proxy records were consistent with temperature oscillations and related changes in organic carbon cycling associated with the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA). Abundance changes in dominant microfossil species, such as the ostracode Paracyprideis pseudopunctillata and agglutinated foraminifers Spiroplectammina biformis and S. earlandi, are used as indicators of less saline, and possibly corrosive/turbid bottom conditions associated with the MCA (~800-1200 CE) and the most recent ~60 years (1950-2013). During these periods, pronounced fluctuations in these species suggest that prolonged seasonal sea-ice melting, changes in riverine inputs and sediment dynamics affected the benthic environment. Taxa analyzed for stable oxygen isotope composition of carbonates show the lowest δ 18 O values during intervals within the MCA and the highest during the late LIA, which is consistent with a 1° to 2°C cooling of bottom waters. Faunal and isotopic changes during the cooler LIA (1300-1850 CE) are most apparent at ~1500-1850 CE and are particularly pronounced during 1850 to ~1900 CE, with a ~0.5 per mil increase in δ 18 O values of carbonates from median values in the analyzed taxa. This very cold 50-year period suggests ... |
format |
Article in Journal/Newspaper |
author |
Gemery, Laura Cronin, Thomas M. Cooper, Lee W. Roberts, Lucy R. Keigwin, Lloyd D. Addison, Jason A. Leng, Melanie J. Lin, Peigen Magen, Cédric Marot, Marci E. Schwartz, Valerie |
author_facet |
Gemery, Laura Cronin, Thomas M. Cooper, Lee W. Roberts, Lucy R. Keigwin, Lloyd D. Addison, Jason A. Leng, Melanie J. Lin, Peigen Magen, Cédric Marot, Marci E. Schwartz, Valerie |
author_sort |
Gemery, Laura |
title |
Multi-proxy record of ocean-climate variability during the last two millennia on the Mackenzie Shelf, Beaufort Sea |
title_short |
Multi-proxy record of ocean-climate variability during the last two millennia on the Mackenzie Shelf, Beaufort Sea |
title_full |
Multi-proxy record of ocean-climate variability during the last two millennia on the Mackenzie Shelf, Beaufort Sea |
title_fullStr |
Multi-proxy record of ocean-climate variability during the last two millennia on the Mackenzie Shelf, Beaufort Sea |
title_full_unstemmed |
Multi-proxy record of ocean-climate variability during the last two millennia on the Mackenzie Shelf, Beaufort Sea |
title_sort |
multi-proxy record of ocean-climate variability during the last two millennia on the mackenzie shelf, beaufort sea |
publishDate |
2023 |
url |
https://pure.au.dk/portal/da/publications/multiproxy-record-of-oceanclimate-variability-during-the-last-two-millennia-on-the-mackenzie-shelf-beaufort-sea(18c53b63-e92c-4cf2-b445-fcacb58c48e7).html https://doi.org/10.47894/mpal.69.3.04 http://www.scopus.com/inward/record.url?scp=85145750718&partnerID=8YFLogxK |
genre |
Arctic Arctic Ocean Beaufort Sea Foraminifera* Mackenzie river Mackenzie Shelf Sea ice |
genre_facet |
Arctic Arctic Ocean Beaufort Sea Foraminifera* Mackenzie river Mackenzie Shelf Sea ice |
op_source |
Gemery , L , Cronin , T M , Cooper , L W , Roberts , L R , Keigwin , L D , Addison , J A , Leng , M J , Lin , P , Magen , C , Marot , M E & Schwartz , V 2023 , ' Multi-proxy record of ocean-climate variability during the last two millennia on the Mackenzie Shelf, Beaufort Sea ' , Micropaleontology , vol. 69 , no. 3 , pp. 345-366 . https://doi.org/10.47894/mpal.69.3.04 |
op_relation |
https://pure.au.dk/portal/da/publications/multiproxy-record-of-oceanclimate-variability-during-the-last-two-millennia-on-the-mackenzie-shelf-beaufort-sea(18c53b63-e92c-4cf2-b445-fcacb58c48e7).html |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.47894/mpal.69.3.04 |
container_title |
Micropaleontology |
container_volume |
69 |
container_issue |
3 |
container_start_page |
345 |
op_container_end_page |
360 |
_version_ |
1786832202073374720 |