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 10–20 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 m...
Published in: | Journal of Glaciology |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2014
|
Subjects: | |
Online Access: | https://eprints.soton.ac.uk/398660/ |
id |
ftsouthampton:oai:eprints.soton.ac.uk:398660 |
---|---|
record_format |
openpolar |
spelling |
ftsouthampton:oai:eprints.soton.ac.uk:398660 2023-07-30T03:55:57+02:00 Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica Craven, M. Galton-Fenzi, B.K. Herraiz-Borreguero, L. Vogel, S.W. Allison, I. 2014-04-01 https://eprints.soton.ac.uk/398660/ English eng Craven, M., Galton-Fenzi, B.K., Herraiz-Borreguero, L., Vogel, S.W. and Allison, I. (2014) Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica. Journal of Glaciology, 60 (220), 383-393. (doi:10.3189/2014JoG13J082 <http://dx.doi.org/10.3189/2014JoG13J082>). Article PeerReviewed 2014 ftsouthampton https://doi.org/10.3189/2014JoG13J082 2023-07-09T22:09:48Z Oceanographic instruments suspended beneath the Amery Ice Shelf, East Antarctica, have recorded sporadic pressure decreases of 10–20 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 3–4 m a–1 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 University of Southampton: e-Prints Soton 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 |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
English |
description |
Oceanographic instruments suspended beneath the Amery Ice Shelf, East Antarctica, have recorded sporadic pressure decreases of 10–20 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 3–4 m a–1 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. Galton-Fenzi, B.K. Herraiz-Borreguero, L. Vogel, S.W. Allison, I. |
spellingShingle |
Craven, M. Galton-Fenzi, B.K. Herraiz-Borreguero, L. Vogel, S.W. Allison, I. Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica |
author_facet |
Craven, M. Galton-Fenzi, B.K. Herraiz-Borreguero, L. Vogel, S.W. 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 |
publishDate |
2014 |
url |
https://eprints.soton.ac.uk/398660/ |
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 |
Craven, M., Galton-Fenzi, B.K., Herraiz-Borreguero, L., Vogel, S.W. and Allison, I. (2014) Platelet ice attachment to instrument strings beneath the Amery Ice Shelf, East Antarctica. Journal of Glaciology, 60 (220), 383-393. (doi:10.3189/2014JoG13J082 <http://dx.doi.org/10.3189/2014JoG13J082>). |
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_ |
1772810355698827264 |