Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica
Oceanographic instruments suspended beneath the Amery Ice Shelf, East Antarctica, have recorded sporadic pressure decreases of 1020 dbar over a few days at three sites where basal marine ice growth is expected. We attribute these events to flotation due to platelet ice accretion on the instrument mo...
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ftunivtasecite:oai:ecite.utas.edu.au:93951 2023-05-15T13:22:02+02:00 Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica Craven, M Warner, RC Galton-Fenzi, B Herraiz Borreguero, L Vogel, SW Allison, I 2014 application/pdf https://doi.org/10.3189/2014JoG13J082 http://ecite.utas.edu.au/93951 en eng Int Glaciol Soc http://ecite.utas.edu.au/93951/1/Craven_2014_Platelet_ice_attachment.pdf http://dx.doi.org/10.3189/2014JoG13J082 Craven, M and Warner, RC and Galton-Fenzi, B and Herraiz Borreguero, L and Vogel, SW and Allison, I, Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica, Journal of Glaciology, 60, (220) pp. 383-393. ISSN 0022-1430 (2014) [Refereed Article] http://ecite.utas.edu.au/93951 Earth Sciences Oceanography Physical Oceanography Refereed Article PeerReviewed 2014 ftunivtasecite https://doi.org/10.3189/2014JoG13J082 2019-12-13T21:56:42Z Oceanographic instruments suspended beneath the Amery Ice Shelf, East Antarctica, have recorded sporadic pressure decreases of 1020 dbar over a few days at three sites where basal marine ice growth is expected. We attribute these events to flotation due to platelet ice accretion on the instrument moorings. Some events were transient, rapidly returning to pre-event pressures, probably through dislodgement of loosely attached crystals. Driven by these pressure changes, temperatures recorded by the shallowest instruments (within 20 m of the shelf base) tracked in situ freezing temperatures during the events. These observations provide indirect evidence for the presence of frazil ice in the sub-ice-shelf mixed layer and for active marine ice accretion. At one site we infer that a dense layer of platelet ice ∼1.5 m thick was accreted to the ice shelf over a 50 day period. Following some permanent abrupt pressure decreases (which we interpret as due to the lodgement of the uppermost instrument at the ice-shelf base), altered background trends in pressure suggest compaction rates of 34 m a1 for the accreted basal platelet layer. Attachment of platelet ice and resulting displacement of moorings has ramifications for project design and instrument deployment, and implications for interpretation of oceanographic data from sub-ice-shelf environments. Article in Journal/Newspaper Amery Ice Shelf Antarc* Antarctica Antarctica Journal East Antarctica Ice Shelf Journal of Glaciology eCite UTAS (University of Tasmania) Amery ENVELOPE(-94.063,-94.063,56.565,56.565) Amery Ice Shelf ENVELOPE(71.000,71.000,-69.750,-69.750) East Antarctica Journal of Glaciology 60 220 383 393 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Physical Oceanography |
spellingShingle |
Earth Sciences Oceanography Physical Oceanography Craven, M Warner, RC Galton-Fenzi, B Herraiz Borreguero, L Vogel, SW Allison, I Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica |
topic_facet |
Earth Sciences Oceanography Physical Oceanography |
description |
Oceanographic instruments suspended beneath the Amery Ice Shelf, East Antarctica, have recorded sporadic pressure decreases of 1020 dbar over a few days at three sites where basal marine ice growth is expected. We attribute these events to flotation due to platelet ice accretion on the instrument moorings. Some events were transient, rapidly returning to pre-event pressures, probably through dislodgement of loosely attached crystals. Driven by these pressure changes, temperatures recorded by the shallowest instruments (within 20 m of the shelf base) tracked in situ freezing temperatures during the events. These observations provide indirect evidence for the presence of frazil ice in the sub-ice-shelf mixed layer and for active marine ice accretion. At one site we infer that a dense layer of platelet ice ∼1.5 m thick was accreted to the ice shelf over a 50 day period. Following some permanent abrupt pressure decreases (which we interpret as due to the lodgement of the uppermost instrument at the ice-shelf base), altered background trends in pressure suggest compaction rates of 34 m a1 for the accreted basal platelet layer. Attachment of platelet ice and resulting displacement of moorings has ramifications for project design and instrument deployment, and implications for interpretation of oceanographic data from sub-ice-shelf environments. |
format |
Article in Journal/Newspaper |
author |
Craven, M Warner, RC Galton-Fenzi, B Herraiz Borreguero, L Vogel, SW Allison, I |
author_facet |
Craven, M Warner, RC Galton-Fenzi, B Herraiz Borreguero, L Vogel, SW Allison, I |
author_sort |
Craven, M |
title |
Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica |
title_short |
Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica |
title_full |
Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica |
title_fullStr |
Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica |
title_full_unstemmed |
Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica |
title_sort |
platelet ice attachment to instrument strings beneath the amery ice shelf, east antarctica |
publisher |
Int Glaciol Soc |
publishDate |
2014 |
url |
https://doi.org/10.3189/2014JoG13J082 http://ecite.utas.edu.au/93951 |
long_lat |
ENVELOPE(-94.063,-94.063,56.565,56.565) ENVELOPE(71.000,71.000,-69.750,-69.750) |
geographic |
Amery Amery Ice Shelf East Antarctica |
geographic_facet |
Amery Amery Ice Shelf East Antarctica |
genre |
Amery Ice Shelf Antarc* Antarctica Antarctica Journal East Antarctica Ice Shelf Journal of Glaciology |
genre_facet |
Amery Ice Shelf Antarc* Antarctica Antarctica Journal East Antarctica Ice Shelf Journal of Glaciology |
op_relation |
http://ecite.utas.edu.au/93951/1/Craven_2014_Platelet_ice_attachment.pdf http://dx.doi.org/10.3189/2014JoG13J082 Craven, M and Warner, RC and Galton-Fenzi, B and Herraiz Borreguero, L and Vogel, SW and Allison, I, Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica, Journal of Glaciology, 60, (220) pp. 383-393. ISSN 0022-1430 (2014) [Refereed Article] http://ecite.utas.edu.au/93951 |
op_doi |
https://doi.org/10.3189/2014JoG13J082 |
container_title |
Journal of Glaciology |
container_volume |
60 |
container_issue |
220 |
container_start_page |
383 |
op_container_end_page |
393 |
_version_ |
1766362936384684032 |