Post-LGM upward shift of the Mediterranean Outflow Water recorded in a contourite drift off NW Spain
The NW Iberian continental margin is characterised by a complex morphology and by a sedimentary system which was highly dynamic over glacial to interglacial times. The sedimentary history of the continental slope was strongly influenced by the interaction of bottom currents with topographic highs of...
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Online Access: | https://oro.open.ac.uk/58398/ https://oro.open.ac.uk/58398/1/1-s2.0-S0025322718303128-main.pdf https://doi.org/10.1016/j.margeo.2018.11.015 |
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ftopenunivgb:oai:oro.open.ac.uk:58398 2023-06-11T04:13:48+02:00 Post-LGM upward shift of the Mediterranean Outflow Water recorded in a contourite drift off NW Spain Petrovic, A. Lantzsch, H. Schwenk, T. Marquardt, J. Titschack, J. Hanebuth, T. J. J. 2019-01 application/pdf https://oro.open.ac.uk/58398/ https://oro.open.ac.uk/58398/1/1-s2.0-S0025322718303128-main.pdf https://doi.org/10.1016/j.margeo.2018.11.015 unknown https://oro.open.ac.uk/58398/1/1-s2.0-S0025322718303128-main.pdf Petrovic, A.; Lantzsch, H.; Schwenk, T.; Marquardt, J. <http://oro.open.ac.uk/view/person/jm39833.html>; Titschack, J. and Hanebuth, T. J. J. (2019). Post-LGM upward shift of the Mediterranean Outflow Water recorded in a contourite drift off NW Spain. Marine Geology, 407 pp. 334–349. Journal Item OU Users Only PeerReviewed 2019 ftopenunivgb https://doi.org/10.1016/j.margeo.2018.11.015 2023-05-28T05:58:45Z The NW Iberian continental margin is characterised by a complex morphology and by a sedimentary system which was highly dynamic over glacial to interglacial times. The sedimentary history of the continental slope was strongly influenced by the interaction of bottom currents with topographic highs of structural origin leading to the accumulation of several sediment drifts. A combined analysis of gravity cores from different water depth with hydroacoustic data reveals the vertical behaviour of the upper Mediterranean Outflow Water (MOW) core after the Last Glacial Maximum (LGM). A coarser grained interval during Deglacial and early Holocene times (17.2 to 9.9 cal ka BP) points to an increase in bottom current strength. This increase in velocity was probably related to oceanic density fronts, which migrated through the 300 m thick transition zone between the underlying Labrador Sea Water and the overlying MOW. Radiocarbon dates timed the current strengthening to 17.2 cal ka BP, and a following weakening of the bottom current to 13.3 cal ka BP at 1965 m water depth and to 9.9 cal ka BP at 1885 m water depth. The depth-dependent current weakening suggests an upward shifting of the transition zone by 80 m that was related either to an overall shallowing of MOW or a vertical contraction of this water mass. The upward movement happened over a time interval of approximately 3.4 thousand years. In addition sediment core analysis reveals significant lateral heterogeneities within cm to dm thick sediment layers in the contourite drift. These heterogeneities suggest a need of a detailed core coverage across current-influenced deposits for palaeoceanographic studies to minimize misinterpretations. Article in Journal/Newspaper Labrador Sea The Open University: Open Research Online (ORO) Marine Geology 407 334 349 |
institution |
Open Polar |
collection |
The Open University: Open Research Online (ORO) |
op_collection_id |
ftopenunivgb |
language |
unknown |
description |
The NW Iberian continental margin is characterised by a complex morphology and by a sedimentary system which was highly dynamic over glacial to interglacial times. The sedimentary history of the continental slope was strongly influenced by the interaction of bottom currents with topographic highs of structural origin leading to the accumulation of several sediment drifts. A combined analysis of gravity cores from different water depth with hydroacoustic data reveals the vertical behaviour of the upper Mediterranean Outflow Water (MOW) core after the Last Glacial Maximum (LGM). A coarser grained interval during Deglacial and early Holocene times (17.2 to 9.9 cal ka BP) points to an increase in bottom current strength. This increase in velocity was probably related to oceanic density fronts, which migrated through the 300 m thick transition zone between the underlying Labrador Sea Water and the overlying MOW. Radiocarbon dates timed the current strengthening to 17.2 cal ka BP, and a following weakening of the bottom current to 13.3 cal ka BP at 1965 m water depth and to 9.9 cal ka BP at 1885 m water depth. The depth-dependent current weakening suggests an upward shifting of the transition zone by 80 m that was related either to an overall shallowing of MOW or a vertical contraction of this water mass. The upward movement happened over a time interval of approximately 3.4 thousand years. In addition sediment core analysis reveals significant lateral heterogeneities within cm to dm thick sediment layers in the contourite drift. These heterogeneities suggest a need of a detailed core coverage across current-influenced deposits for palaeoceanographic studies to minimize misinterpretations. |
format |
Article in Journal/Newspaper |
author |
Petrovic, A. Lantzsch, H. Schwenk, T. Marquardt, J. Titschack, J. Hanebuth, T. J. J. |
spellingShingle |
Petrovic, A. Lantzsch, H. Schwenk, T. Marquardt, J. Titschack, J. Hanebuth, T. J. J. Post-LGM upward shift of the Mediterranean Outflow Water recorded in a contourite drift off NW Spain |
author_facet |
Petrovic, A. Lantzsch, H. Schwenk, T. Marquardt, J. Titschack, J. Hanebuth, T. J. J. |
author_sort |
Petrovic, A. |
title |
Post-LGM upward shift of the Mediterranean Outflow Water recorded in a contourite drift off NW Spain |
title_short |
Post-LGM upward shift of the Mediterranean Outflow Water recorded in a contourite drift off NW Spain |
title_full |
Post-LGM upward shift of the Mediterranean Outflow Water recorded in a contourite drift off NW Spain |
title_fullStr |
Post-LGM upward shift of the Mediterranean Outflow Water recorded in a contourite drift off NW Spain |
title_full_unstemmed |
Post-LGM upward shift of the Mediterranean Outflow Water recorded in a contourite drift off NW Spain |
title_sort |
post-lgm upward shift of the mediterranean outflow water recorded in a contourite drift off nw spain |
publishDate |
2019 |
url |
https://oro.open.ac.uk/58398/ https://oro.open.ac.uk/58398/1/1-s2.0-S0025322718303128-main.pdf https://doi.org/10.1016/j.margeo.2018.11.015 |
genre |
Labrador Sea |
genre_facet |
Labrador Sea |
op_relation |
https://oro.open.ac.uk/58398/1/1-s2.0-S0025322718303128-main.pdf Petrovic, A.; Lantzsch, H.; Schwenk, T.; Marquardt, J. <http://oro.open.ac.uk/view/person/jm39833.html>; Titschack, J. and Hanebuth, T. J. J. (2019). Post-LGM upward shift of the Mediterranean Outflow Water recorded in a contourite drift off NW Spain. Marine Geology, 407 pp. 334–349. |
op_doi |
https://doi.org/10.1016/j.margeo.2018.11.015 |
container_title |
Marine Geology |
container_volume |
407 |
container_start_page |
334 |
op_container_end_page |
349 |
_version_ |
1768391139648339968 |