Iceberg scours, pits, and pockmarks in the North Falkland Basin
Glaciation in the Southern Hemisphere is limited by the availability of land from which to seed ice sheets. The extents of the Antarctic, Patagonian, and New Zealand Ice Sheets at the Last Glacial Maximum (LGM) are relatively well known, although the rates and styles of their retreat after the LGM a...
Published in: | Marine Geology |
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Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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2017
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Online Access: | https://pure.qub.ac.uk/en/publications/iceberg-scours-pits-and-pockmarks-in-the-north-falkland-basin(e5ac66c0-a8e3-41ce-a062-227d99ddab8d).html https://doi.org/10.1016/j.margeo.2017.03.001 https://pureadmin.qub.ac.uk/ws/files/149494285/1_s2.0_S0025322716302997_main.pdf http://www.scopus.com/inward/record.url?scp=85016261207&partnerID=8YFLogxK |
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ftqueensubelpubl:oai:pure.qub.ac.uk/portal:publications/e5ac66c0-a8e3-41ce-a062-227d99ddab8d 2023-05-15T13:56:19+02:00 Iceberg scours, pits, and pockmarks in the North Falkland Basin Brown, Christopher S. Newton, Andrew M.W. Huuse, Mads Buckley, Francis 2017-04-10 application/pdf https://pure.qub.ac.uk/en/publications/iceberg-scours-pits-and-pockmarks-in-the-north-falkland-basin(e5ac66c0-a8e3-41ce-a062-227d99ddab8d).html https://doi.org/10.1016/j.margeo.2017.03.001 https://pureadmin.qub.ac.uk/ws/files/149494285/1_s2.0_S0025322716302997_main.pdf http://www.scopus.com/inward/record.url?scp=85016261207&partnerID=8YFLogxK eng eng info:eu-repo/semantics/openAccess Brown , C S , Newton , A M W , Huuse , M & Buckley , F 2017 , ' Iceberg scours, pits, and pockmarks in the North Falkland Basin ' , Marine Geology , vol. 386 , pp. 140-152 . https://doi.org/10.1016/j.margeo.2017.03.001 Antarctic Peninsula Icebergs North Falkland Basin Pits Pockmarks Scours /dk/atira/pure/subjectarea/asjc/1900/1910 Oceanography /dk/atira/pure/subjectarea/asjc/1900/1907 Geology /dk/atira/pure/subjectarea/asjc/1900/1906 Geochemistry and Petrology /dk/atira/pure/sustainabledevelopmentgoals/climate_action SDG 13 - Climate Action article 2017 ftqueensubelpubl https://doi.org/10.1016/j.margeo.2017.03.001 2022-02-09T22:27:14Z Glaciation in the Southern Hemisphere is limited by the availability of land from which to seed ice sheets. The extents of the Antarctic, Patagonian, and New Zealand Ice Sheets at the Last Glacial Maximum (LGM) are relatively well known, although the rates and styles of their retreat after the LGM are poorly constrained, particularly in Antarctica. Offshore records of glaciation are relatively sparse in the Southern Hemisphere despite the potential ocean-climate insights that can be gained from records of glaciation that are preserved offshore. In this study, we document the occurrence of iceberg scours and accompanying pits within the North Falkland Basin (c. 50° S) and discuss their origin. The cross-sectional shapes of scours are u- to v-shaped and occur in present-day water depths of 280 to 460 m. Individual scours are up to 38 km long, 1 km wide, and up to ~ 10 m deep. The scours are observed as erosional linear to curvilinear depressions, showing only one point of contact between the iceberg and seafloor, often with raised berms, composed of excavated material, identified either side of the main depression. Undulating width of scours is interpreted as an effect of rotation of the iceberg keel during scour excavation. The elongate morphology of the scours differentiates them from asymmetrical pits, interpreted to represent iceberg impact pits, and symmetrical pockmarks, interpreted to form due to fluid expulsion. In cross-section the differentiation is highly interpretative, but the 3D bathymetric expression is unequivocal. The sinusoidal character of the scours suggests the interaction between local tidal currents and the East Falkland/Malvinas Currents in the North Falkland Basin at the time of formation. Offshore and onshore landscape analysis is used to determine potential sources of icebergs and suggests that they were most likely sourced from the Antarctic Peninsula. These results inform our understanding of Southern Hemisphere ocean-climate interactions during the last glacial cycle and suggest that the East Falklands/Malvinas Current, a key current in the Southern Hemisphere bringing cold, low-salinity Antarctic-derived waters into the South Atlantic, was in operation during the last glacial cycle. The accumulation of icebergs west of the Falkland Islands would also result in further cooling from fresh, meltwater perturbations, enhancing the development of a potential ice-bridge along the Argentinian coast. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica Iceberg* Queen's University Belfast Research Portal Antarctic The Antarctic Antarctic Peninsula New Zealand Marine Geology 386 140 152 |
institution |
Open Polar |
collection |
Queen's University Belfast Research Portal |
op_collection_id |
ftqueensubelpubl |
language |
English |
topic |
Antarctic Peninsula Icebergs North Falkland Basin Pits Pockmarks Scours /dk/atira/pure/subjectarea/asjc/1900/1910 Oceanography /dk/atira/pure/subjectarea/asjc/1900/1907 Geology /dk/atira/pure/subjectarea/asjc/1900/1906 Geochemistry and Petrology /dk/atira/pure/sustainabledevelopmentgoals/climate_action SDG 13 - Climate Action |
spellingShingle |
Antarctic Peninsula Icebergs North Falkland Basin Pits Pockmarks Scours /dk/atira/pure/subjectarea/asjc/1900/1910 Oceanography /dk/atira/pure/subjectarea/asjc/1900/1907 Geology /dk/atira/pure/subjectarea/asjc/1900/1906 Geochemistry and Petrology /dk/atira/pure/sustainabledevelopmentgoals/climate_action SDG 13 - Climate Action Brown, Christopher S. Newton, Andrew M.W. Huuse, Mads Buckley, Francis Iceberg scours, pits, and pockmarks in the North Falkland Basin |
topic_facet |
Antarctic Peninsula Icebergs North Falkland Basin Pits Pockmarks Scours /dk/atira/pure/subjectarea/asjc/1900/1910 Oceanography /dk/atira/pure/subjectarea/asjc/1900/1907 Geology /dk/atira/pure/subjectarea/asjc/1900/1906 Geochemistry and Petrology /dk/atira/pure/sustainabledevelopmentgoals/climate_action SDG 13 - Climate Action |
description |
Glaciation in the Southern Hemisphere is limited by the availability of land from which to seed ice sheets. The extents of the Antarctic, Patagonian, and New Zealand Ice Sheets at the Last Glacial Maximum (LGM) are relatively well known, although the rates and styles of their retreat after the LGM are poorly constrained, particularly in Antarctica. Offshore records of glaciation are relatively sparse in the Southern Hemisphere despite the potential ocean-climate insights that can be gained from records of glaciation that are preserved offshore. In this study, we document the occurrence of iceberg scours and accompanying pits within the North Falkland Basin (c. 50° S) and discuss their origin. The cross-sectional shapes of scours are u- to v-shaped and occur in present-day water depths of 280 to 460 m. Individual scours are up to 38 km long, 1 km wide, and up to ~ 10 m deep. The scours are observed as erosional linear to curvilinear depressions, showing only one point of contact between the iceberg and seafloor, often with raised berms, composed of excavated material, identified either side of the main depression. Undulating width of scours is interpreted as an effect of rotation of the iceberg keel during scour excavation. The elongate morphology of the scours differentiates them from asymmetrical pits, interpreted to represent iceberg impact pits, and symmetrical pockmarks, interpreted to form due to fluid expulsion. In cross-section the differentiation is highly interpretative, but the 3D bathymetric expression is unequivocal. The sinusoidal character of the scours suggests the interaction between local tidal currents and the East Falkland/Malvinas Currents in the North Falkland Basin at the time of formation. Offshore and onshore landscape analysis is used to determine potential sources of icebergs and suggests that they were most likely sourced from the Antarctic Peninsula. These results inform our understanding of Southern Hemisphere ocean-climate interactions during the last glacial cycle and suggest that the East Falklands/Malvinas Current, a key current in the Southern Hemisphere bringing cold, low-salinity Antarctic-derived waters into the South Atlantic, was in operation during the last glacial cycle. The accumulation of icebergs west of the Falkland Islands would also result in further cooling from fresh, meltwater perturbations, enhancing the development of a potential ice-bridge along the Argentinian coast. |
format |
Article in Journal/Newspaper |
author |
Brown, Christopher S. Newton, Andrew M.W. Huuse, Mads Buckley, Francis |
author_facet |
Brown, Christopher S. Newton, Andrew M.W. Huuse, Mads Buckley, Francis |
author_sort |
Brown, Christopher S. |
title |
Iceberg scours, pits, and pockmarks in the North Falkland Basin |
title_short |
Iceberg scours, pits, and pockmarks in the North Falkland Basin |
title_full |
Iceberg scours, pits, and pockmarks in the North Falkland Basin |
title_fullStr |
Iceberg scours, pits, and pockmarks in the North Falkland Basin |
title_full_unstemmed |
Iceberg scours, pits, and pockmarks in the North Falkland Basin |
title_sort |
iceberg scours, pits, and pockmarks in the north falkland basin |
publishDate |
2017 |
url |
https://pure.qub.ac.uk/en/publications/iceberg-scours-pits-and-pockmarks-in-the-north-falkland-basin(e5ac66c0-a8e3-41ce-a062-227d99ddab8d).html https://doi.org/10.1016/j.margeo.2017.03.001 https://pureadmin.qub.ac.uk/ws/files/149494285/1_s2.0_S0025322716302997_main.pdf http://www.scopus.com/inward/record.url?scp=85016261207&partnerID=8YFLogxK |
geographic |
Antarctic The Antarctic Antarctic Peninsula New Zealand |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula New Zealand |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Iceberg* |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Iceberg* |
op_source |
Brown , C S , Newton , A M W , Huuse , M & Buckley , F 2017 , ' Iceberg scours, pits, and pockmarks in the North Falkland Basin ' , Marine Geology , vol. 386 , pp. 140-152 . https://doi.org/10.1016/j.margeo.2017.03.001 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.margeo.2017.03.001 |
container_title |
Marine Geology |
container_volume |
386 |
container_start_page |
140 |
op_container_end_page |
152 |
_version_ |
1766263748227497984 |