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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ftunivcam:oai:www.repository.cam.ac.uk:1810/332105 2024-01-14T10:06:26+01:00 A ~240 ka record of Ice Sheet and Ocean interactions on the Snorri Drift, SW of Iceland Andrews, JT McCave, IN Syvitski, J 2021-12-08T10:16:12Z application/octet-stream https://www.repository.cam.ac.uk/handle/1810/332105 https://doi.org/10.17863/CAM.79551 eng eng Elsevier BV Department of Earth Sciences http://dx.doi.org/10.1016/j.gloplacha.2021.103498 Global and Planetary Change https://www.repository.cam.ac.uk/handle/1810/332105 doi:10.17863/CAM.79551 All Rights Reserved http://www.rioxx.net/licenses/all-rights-reserved Snorri Drift Deep Northern Boundary Current MIS 1-7 Mineral composition Sortable silt Flow speed Saline gravity current IRD Article 2021 ftunivcam https://doi.org/10.17863/CAM.79551 2023-12-21T23:22:13Z 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 Apollo - University of Cambridge Repository Greenland |
institution |
Open Polar |
collection |
Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
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, JT McCave, IN Syvitski, J 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, JT McCave, IN Syvitski, J |
author_facet |
Andrews, JT McCave, IN Syvitski, J |
author_sort |
Andrews, JT |
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://www.repository.cam.ac.uk/handle/1810/332105 https://doi.org/10.17863/CAM.79551 |
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_relation |
https://www.repository.cam.ac.uk/handle/1810/332105 doi:10.17863/CAM.79551 |
op_rights |
All Rights Reserved http://www.rioxx.net/licenses/all-rights-reserved |
op_doi |
https://doi.org/10.17863/CAM.79551 |
_version_ |
1788060903256621056 |