A ~240 ka record of Ice Sheet and Ocean interactions on the Snorri Drift, SW of Iceland
Core MD99-2323 was extracted from the Snorri Drift at a water depth of 1062 m, just south of the Denmark Strait, and ~120 km from the Last Glacial Maximum (LGM) margins of the Iceland and East Greenland Ice Sheets. The core chronology (~7.5 to 240 cal ka) is derived from radiocarbon dates, marker te...
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Language: | English |
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Elsevier BV
2021
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Online Access: | https://archimer.ifremer.fr/doc/00691/80344/83434.pdf https://doi.org/10.1016/j.gloplacha.2021.103498 https://archimer.ifremer.fr/doc/00691/80344/ |
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ftarchimer:oai:archimer.ifremer.fr:80344 2023-05-15T16:00:41+02:00 A ~240 ka record of Ice Sheet and Ocean interactions on the Snorri Drift, SW of Iceland Andrews, J.t. Mccave, I.n. Syvitski, Jaia 2021-06 application/pdf https://archimer.ifremer.fr/doc/00691/80344/83434.pdf https://doi.org/10.1016/j.gloplacha.2021.103498 https://archimer.ifremer.fr/doc/00691/80344/ eng eng Elsevier BV https://archimer.ifremer.fr/doc/00691/80344/83434.pdf doi:10.1016/j.gloplacha.2021.103498 https://archimer.ifremer.fr/doc/00691/80344/ info:eu-repo/semantics/openAccess restricted use Global And Planetary Change (0921-8181) (Elsevier BV), 2021-06 , Vol. 201 , P. 103498 (12p.) Snorri Drift Deep Northern Boundary Current MIS 1-7 Mineral composition Sortable silt Flow speed Saline gravity current IRD text Publication info:eu-repo/semantics/article 2021 ftarchimer https://doi.org/10.1016/j.gloplacha.2021.103498 2022-05-03T22:50:02Z Core MD99-2323 was extracted from the Snorri Drift at a water depth of 1062 m, just south of the Denmark Strait, and ~120 km from the Last Glacial Maximum (LGM) margins of the Iceland and East Greenland Ice Sheets. The core chronology (~7.5 to 240 cal ka) is derived from radiocarbon dates, marker tephra, paleomagnetic excursion, and correlation with North Atlantic δ18O records on Neogloboquadrina pachyderma (δ18ONp). Sedimentation averaged ~7.5 cm/kyr. Records of proxy flow speed, ice rafted debris (IRD) and oxygen isotopes show that many IRD abundance peaks represent winnowing of the fine fraction by faster flows rather than pulses of increased IRD flux. The overall pattern of flow speed does not resemble the classic fast interglacial/slow glacial pattern seen in records of Nordic Sea overflow, rather the current record is suggested to be partly controlled by the production of brine-driven gravity flows from adjacent ice fronts, especially during cold periods. On a smaller scale the usual glacial/slow – interglacial/fast pattern appears to be the case during ~5 kyr oscillations during Marine Isotope Stage (MIS) 6 where periodic low flow speed is matched by high values of planktonic oxygen isotope ratios. Eight peaks in quartz wt% reflect increased contributions from glacial erosion of Precambrian and Caledonian bedrock from E and NE Greenland; peaks in dolomite may reflect glacial-marine transport from the Laurentide Ice Sheet. Cross wavelet analysis of the δ18ONp versus sortable silt and quartz records indicate significant precession and obliquity periodicities, but with little temporal correlations due to leads and lags in responses. Article in Journal/Newspaper Denmark Strait East Greenland Greenland Ice Sheet Iceland Neogloboquadrina pachyderma Nordic Sea North Atlantic Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Greenland Global and Planetary Change 201 103498 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
Snorri Drift Deep Northern Boundary Current MIS 1-7 Mineral composition Sortable silt Flow speed Saline gravity current IRD |
spellingShingle |
Snorri Drift Deep Northern Boundary Current MIS 1-7 Mineral composition Sortable silt Flow speed Saline gravity current IRD Andrews, J.t. Mccave, I.n. Syvitski, Jaia A ~240 ka record of Ice Sheet and Ocean interactions on the Snorri Drift, SW of Iceland |
topic_facet |
Snorri Drift Deep Northern Boundary Current MIS 1-7 Mineral composition Sortable silt Flow speed Saline gravity current IRD |
description |
Core MD99-2323 was extracted from the Snorri Drift at a water depth of 1062 m, just south of the Denmark Strait, and ~120 km from the Last Glacial Maximum (LGM) margins of the Iceland and East Greenland Ice Sheets. The core chronology (~7.5 to 240 cal ka) is derived from radiocarbon dates, marker tephra, paleomagnetic excursion, and correlation with North Atlantic δ18O records on Neogloboquadrina pachyderma (δ18ONp). Sedimentation averaged ~7.5 cm/kyr. Records of proxy flow speed, ice rafted debris (IRD) and oxygen isotopes show that many IRD abundance peaks represent winnowing of the fine fraction by faster flows rather than pulses of increased IRD flux. The overall pattern of flow speed does not resemble the classic fast interglacial/slow glacial pattern seen in records of Nordic Sea overflow, rather the current record is suggested to be partly controlled by the production of brine-driven gravity flows from adjacent ice fronts, especially during cold periods. On a smaller scale the usual glacial/slow – interglacial/fast pattern appears to be the case during ~5 kyr oscillations during Marine Isotope Stage (MIS) 6 where periodic low flow speed is matched by high values of planktonic oxygen isotope ratios. Eight peaks in quartz wt% reflect increased contributions from glacial erosion of Precambrian and Caledonian bedrock from E and NE Greenland; peaks in dolomite may reflect glacial-marine transport from the Laurentide Ice Sheet. Cross wavelet analysis of the δ18ONp versus sortable silt and quartz records indicate significant precession and obliquity periodicities, but with little temporal correlations due to leads and lags in responses. |
format |
Article in Journal/Newspaper |
author |
Andrews, J.t. Mccave, I.n. Syvitski, Jaia |
author_facet |
Andrews, J.t. Mccave, I.n. Syvitski, Jaia |
author_sort |
Andrews, J.t. |
title |
A ~240 ka record of Ice Sheet and Ocean interactions on the Snorri Drift, SW of Iceland |
title_short |
A ~240 ka record of Ice Sheet and Ocean interactions on the Snorri Drift, SW of Iceland |
title_full |
A ~240 ka record of Ice Sheet and Ocean interactions on the Snorri Drift, SW of Iceland |
title_fullStr |
A ~240 ka record of Ice Sheet and Ocean interactions on the Snorri Drift, SW of Iceland |
title_full_unstemmed |
A ~240 ka record of Ice Sheet and Ocean interactions on the Snorri Drift, SW of Iceland |
title_sort |
~240 ka record of ice sheet and ocean interactions on the snorri drift, sw of iceland |
publisher |
Elsevier BV |
publishDate |
2021 |
url |
https://archimer.ifremer.fr/doc/00691/80344/83434.pdf https://doi.org/10.1016/j.gloplacha.2021.103498 https://archimer.ifremer.fr/doc/00691/80344/ |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Denmark Strait East Greenland Greenland Ice Sheet Iceland Neogloboquadrina pachyderma Nordic Sea North Atlantic |
genre_facet |
Denmark Strait East Greenland Greenland Ice Sheet Iceland Neogloboquadrina pachyderma Nordic Sea North Atlantic |
op_source |
Global And Planetary Change (0921-8181) (Elsevier BV), 2021-06 , Vol. 201 , P. 103498 (12p.) |
op_relation |
https://archimer.ifremer.fr/doc/00691/80344/83434.pdf doi:10.1016/j.gloplacha.2021.103498 https://archimer.ifremer.fr/doc/00691/80344/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1016/j.gloplacha.2021.103498 |
container_title |
Global and Planetary Change |
container_volume |
201 |
container_start_page |
103498 |
_version_ |
1766396688549806080 |