Westward bottom currents along the margin of the South Shetland Island Arc
Existing information is synthesized and new data presented to describe the flow of near-bottom water from the Weddell Sea into the Scotia Sea and westward through Drake Passage along the continental slope. The water characteristics and currents along the northern margins of the South Sandwich Island...
Published in: | Deep Sea Research Part A. Oceanographic Research Papers |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Pergamon Press
1988
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Online Access: | https://oceanrep.geomar.de/id/eprint/31974/ https://oceanrep.geomar.de/id/eprint/31974/1/Zenk_Westward.pdf https://doi.org/10.1016/0198-0149(88)90040-4 |
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ftoceanrep:oai:oceanrep.geomar.de:31974 2023-05-15T14:15:46+02:00 Westward bottom currents along the margin of the South Shetland Island Arc Nowlin, W. D. Zenk, Walter 1988 text https://oceanrep.geomar.de/id/eprint/31974/ https://oceanrep.geomar.de/id/eprint/31974/1/Zenk_Westward.pdf https://doi.org/10.1016/0198-0149(88)90040-4 en eng Pergamon Press https://oceanrep.geomar.de/id/eprint/31974/1/Zenk_Westward.pdf Nowlin, W. D. and Zenk, W. (1988) Westward bottom currents along the margin of the South Shetland Island Arc. Deep Sea Research Part A: Oceanographic Research Papers, 35 (2). pp. 269-301. DOI 10.1016/0198-0149(88)90040-4 <https://doi.org/10.1016/0198-0149%2888%2990040-4>. doi:10.1016/0198-0149(88)90040-4 cc_by_3.0 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 1988 ftoceanrep https://doi.org/10.1016/0198-0149(88)90040-4 2023-04-07T15:24:35Z Existing information is synthesized and new data presented to describe the flow of near-bottom water from the Weddell Sea into the Scotia Sea and westward through Drake Passage along the continental slope. The water characteristics and currents along the northern margins of the South Sandwich Island Arc are examined. Long-term current measurements in the bottom waters at locations over the outer shelf and slope and along the continental rise show persistent flow from Atlantic to Pacific along isobaths at speeds of 10–20 cm s−1. Three sources for the waters in these currents are identified and discussed. At the deepest levels, Weddell Sea Deep Water enters the Scotia Sea near 40°W through a depression in the South Scotia Arc and then flows westward, constrained by the bottom topography. This cold, fresh, oxygenated bottom water then flows west to enter Drake Passage via a gap in the Shackleton Fracture Zone at the base of the continental slope northwest of Elephant Island. Mid-depth water may flow from the Weddell Sea to the Scotia Sea through the Powell Basin (sill depth approximately 2000 m) located west of South Orkney Island near 48°W. The westward flowing waters along the shelf and upper continental slope, which are denser than those immediately offshore, may be a continuation of the Polar Slope Current from the Weddell Sea or may be derived principally by convection from the shelves of the South Sandwich Island Arc. A vertical section north of Elephant Island shows downslope convection off the shelf, analogous to the observed at many locations around Antartica. Article in Journal/Newspaper antartic* Drake Passage Elephant Island Scotia Sea Weddell Sea OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Drake Passage Elephant Island ENVELOPE(-55.184,-55.184,-61.085,-61.085) Pacific Powell Basin ENVELOPE(-49.500,-49.500,-62.250,-62.250) Scotia Sea Shackleton Shackleton Fracture Zone ENVELOPE(-60.000,-60.000,-60.000,-60.000) Weddell Weddell Sea Deep Sea Research Part A. Oceanographic Research Papers 35 2 269 301 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Existing information is synthesized and new data presented to describe the flow of near-bottom water from the Weddell Sea into the Scotia Sea and westward through Drake Passage along the continental slope. The water characteristics and currents along the northern margins of the South Sandwich Island Arc are examined. Long-term current measurements in the bottom waters at locations over the outer shelf and slope and along the continental rise show persistent flow from Atlantic to Pacific along isobaths at speeds of 10–20 cm s−1. Three sources for the waters in these currents are identified and discussed. At the deepest levels, Weddell Sea Deep Water enters the Scotia Sea near 40°W through a depression in the South Scotia Arc and then flows westward, constrained by the bottom topography. This cold, fresh, oxygenated bottom water then flows west to enter Drake Passage via a gap in the Shackleton Fracture Zone at the base of the continental slope northwest of Elephant Island. Mid-depth water may flow from the Weddell Sea to the Scotia Sea through the Powell Basin (sill depth approximately 2000 m) located west of South Orkney Island near 48°W. The westward flowing waters along the shelf and upper continental slope, which are denser than those immediately offshore, may be a continuation of the Polar Slope Current from the Weddell Sea or may be derived principally by convection from the shelves of the South Sandwich Island Arc. A vertical section north of Elephant Island shows downslope convection off the shelf, analogous to the observed at many locations around Antartica. |
format |
Article in Journal/Newspaper |
author |
Nowlin, W. D. Zenk, Walter |
spellingShingle |
Nowlin, W. D. Zenk, Walter Westward bottom currents along the margin of the South Shetland Island Arc |
author_facet |
Nowlin, W. D. Zenk, Walter |
author_sort |
Nowlin, W. D. |
title |
Westward bottom currents along the margin of the South Shetland Island Arc |
title_short |
Westward bottom currents along the margin of the South Shetland Island Arc |
title_full |
Westward bottom currents along the margin of the South Shetland Island Arc |
title_fullStr |
Westward bottom currents along the margin of the South Shetland Island Arc |
title_full_unstemmed |
Westward bottom currents along the margin of the South Shetland Island Arc |
title_sort |
westward bottom currents along the margin of the south shetland island arc |
publisher |
Pergamon Press |
publishDate |
1988 |
url |
https://oceanrep.geomar.de/id/eprint/31974/ https://oceanrep.geomar.de/id/eprint/31974/1/Zenk_Westward.pdf https://doi.org/10.1016/0198-0149(88)90040-4 |
long_lat |
ENVELOPE(-55.184,-55.184,-61.085,-61.085) ENVELOPE(-49.500,-49.500,-62.250,-62.250) ENVELOPE(-60.000,-60.000,-60.000,-60.000) |
geographic |
Drake Passage Elephant Island Pacific Powell Basin Scotia Sea Shackleton Shackleton Fracture Zone Weddell Weddell Sea |
geographic_facet |
Drake Passage Elephant Island Pacific Powell Basin Scotia Sea Shackleton Shackleton Fracture Zone Weddell Weddell Sea |
genre |
antartic* Drake Passage Elephant Island Scotia Sea Weddell Sea |
genre_facet |
antartic* Drake Passage Elephant Island Scotia Sea Weddell Sea |
op_relation |
https://oceanrep.geomar.de/id/eprint/31974/1/Zenk_Westward.pdf Nowlin, W. D. and Zenk, W. (1988) Westward bottom currents along the margin of the South Shetland Island Arc. Deep Sea Research Part A: Oceanographic Research Papers, 35 (2). pp. 269-301. DOI 10.1016/0198-0149(88)90040-4 <https://doi.org/10.1016/0198-0149%2888%2990040-4>. doi:10.1016/0198-0149(88)90040-4 |
op_rights |
cc_by_3.0 info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/0198-0149(88)90040-4 |
container_title |
Deep Sea Research Part A. Oceanographic Research Papers |
container_volume |
35 |
container_issue |
2 |
container_start_page |
269 |
op_container_end_page |
301 |
_version_ |
1766288052671479808 |