Deepwater circulation on Blake Outer Ridge (western North Atlantic) during the Holocene, Younger Dryas, and Last Glacial Maximum
Three depth transects containing a total of 33 sediment cores were investigated along the Blake Outer Ridge in the western subtropical North Atlantic. Sortable silt mean () grain size and stable isotope records were used to assess the position and relative intensity of the Western Boundary Undercurr...
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American Geophysical Union
2008
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ftunivcardiff:oai:https://orca.cardiff.ac.uk:11284 2023-05-15T17:13:54+02:00 Deepwater circulation on Blake Outer Ridge (western North Atlantic) during the Holocene, Younger Dryas, and Last Glacial Maximum Evans, Helena K. Hall, Ian Robert 2008 application/pdf https://orca.cardiff.ac.uk/id/eprint/11284/ https://doi.org/10.1029/2007GC001771 https://orca.cardiff.ac.uk/id/eprint/11284/1/Evans%202008.pdf en eng American Geophysical Union https://orca.cardiff.ac.uk/id/eprint/11284/1/Evans%202008.pdf Evans, Helena K. https://orca.cardiff.ac.uk/view/cardiffauthors/A0643287.html and Hall, Ian Robert https://orca.cardiff.ac.uk/view/cardiffauthors/A002402L.html orcid:0000-0001-6960-1419 orcid:0000-0001-6960-1419 2008. Deepwater circulation on Blake Outer Ridge (western North Atlantic) during the Holocene, Younger Dryas, and Last Glacial Maximum. Geochemistry Geophysics Geosystems 9 (3) , Q03023. 10.1029/2007GC001771 https://doi.org/10.1029/2007GC001771 file https://orca.cardiff.ac.uk/11284/1/Evans%202008.pdf doi:10.1029/2007GC001771 QE Geology Article PeerReviewed 2008 ftunivcardiff https://doi.org/10.1029/2007GC001771 2022-10-20T22:34:33Z Three depth transects containing a total of 33 sediment cores were investigated along the Blake Outer Ridge in the western subtropical North Atlantic. Sortable silt mean () grain size and stable isotope records were used to assess the position and relative intensity of the Western Boundary Undercurrent (WBUC) during the Holocene, the Last Glacial Maximum (LGM), and the Younger Dryas (YD) intervals. The Holocene reconstruction is consistent with modern physical and chemical hydrographic measurements in the area, suggesting a deep position for the fast flowing core of the WBUC (3000–4000 m, deepening to ∼4500 m water depth on the ridge flanks) and a water column dominated by North Atlantic Deep Water (NADW). The LGM and YD reconstructions show that a comparable hydrographic regime was present during both these intervals, suggesting a similar mode of circulation that was appreciably different from the Holocene reconstruction. The WBUC's zone of maximum flow speed during these intervals is suggested to have shifted above 2500 m water depth, consistent with nutrient depleted Glacial North Atlantic Intermediate Water formation with an increasing influence of Southern Source Water (SSW) beneath. Below 4000 m water depth, results hint at increased SSW flow vigor during both the LGM and YD with higher flow speeds than during the Holocene. This study provides a framework for aiding the interpretation of time series records of paleocurrent flow speed changes in the region of the WBUC. Article in Journal/Newspaper NADW North Atlantic Deep Water North Atlantic Cardiff University: ORCA (Online Research @ Cardiff) Geochemistry, Geophysics, Geosystems 9 3 n/a n/a |
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Open Polar |
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Cardiff University: ORCA (Online Research @ Cardiff) |
op_collection_id |
ftunivcardiff |
language |
English |
topic |
QE Geology |
spellingShingle |
QE Geology Evans, Helena K. Hall, Ian Robert Deepwater circulation on Blake Outer Ridge (western North Atlantic) during the Holocene, Younger Dryas, and Last Glacial Maximum |
topic_facet |
QE Geology |
description |
Three depth transects containing a total of 33 sediment cores were investigated along the Blake Outer Ridge in the western subtropical North Atlantic. Sortable silt mean () grain size and stable isotope records were used to assess the position and relative intensity of the Western Boundary Undercurrent (WBUC) during the Holocene, the Last Glacial Maximum (LGM), and the Younger Dryas (YD) intervals. The Holocene reconstruction is consistent with modern physical and chemical hydrographic measurements in the area, suggesting a deep position for the fast flowing core of the WBUC (3000–4000 m, deepening to ∼4500 m water depth on the ridge flanks) and a water column dominated by North Atlantic Deep Water (NADW). The LGM and YD reconstructions show that a comparable hydrographic regime was present during both these intervals, suggesting a similar mode of circulation that was appreciably different from the Holocene reconstruction. The WBUC's zone of maximum flow speed during these intervals is suggested to have shifted above 2500 m water depth, consistent with nutrient depleted Glacial North Atlantic Intermediate Water formation with an increasing influence of Southern Source Water (SSW) beneath. Below 4000 m water depth, results hint at increased SSW flow vigor during both the LGM and YD with higher flow speeds than during the Holocene. This study provides a framework for aiding the interpretation of time series records of paleocurrent flow speed changes in the region of the WBUC. |
format |
Article in Journal/Newspaper |
author |
Evans, Helena K. Hall, Ian Robert |
author_facet |
Evans, Helena K. Hall, Ian Robert |
author_sort |
Evans, Helena K. |
title |
Deepwater circulation on Blake Outer Ridge (western North Atlantic) during the Holocene, Younger Dryas, and Last Glacial Maximum |
title_short |
Deepwater circulation on Blake Outer Ridge (western North Atlantic) during the Holocene, Younger Dryas, and Last Glacial Maximum |
title_full |
Deepwater circulation on Blake Outer Ridge (western North Atlantic) during the Holocene, Younger Dryas, and Last Glacial Maximum |
title_fullStr |
Deepwater circulation on Blake Outer Ridge (western North Atlantic) during the Holocene, Younger Dryas, and Last Glacial Maximum |
title_full_unstemmed |
Deepwater circulation on Blake Outer Ridge (western North Atlantic) during the Holocene, Younger Dryas, and Last Glacial Maximum |
title_sort |
deepwater circulation on blake outer ridge (western north atlantic) during the holocene, younger dryas, and last glacial maximum |
publisher |
American Geophysical Union |
publishDate |
2008 |
url |
https://orca.cardiff.ac.uk/id/eprint/11284/ https://doi.org/10.1029/2007GC001771 https://orca.cardiff.ac.uk/id/eprint/11284/1/Evans%202008.pdf |
genre |
NADW North Atlantic Deep Water North Atlantic |
genre_facet |
NADW North Atlantic Deep Water North Atlantic |
op_relation |
https://orca.cardiff.ac.uk/id/eprint/11284/1/Evans%202008.pdf Evans, Helena K. https://orca.cardiff.ac.uk/view/cardiffauthors/A0643287.html and Hall, Ian Robert https://orca.cardiff.ac.uk/view/cardiffauthors/A002402L.html orcid:0000-0001-6960-1419 orcid:0000-0001-6960-1419 2008. Deepwater circulation on Blake Outer Ridge (western North Atlantic) during the Holocene, Younger Dryas, and Last Glacial Maximum. Geochemistry Geophysics Geosystems 9 (3) , Q03023. 10.1029/2007GC001771 https://doi.org/10.1029/2007GC001771 file https://orca.cardiff.ac.uk/11284/1/Evans%202008.pdf doi:10.1029/2007GC001771 |
op_doi |
https://doi.org/10.1029/2007GC001771 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
9 |
container_issue |
3 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1766071092904984576 |