Survey on moving ice
In order to measure ice deformation at frequent intervals across the Brunt Ice Shelf, Antarctica, 64 markers were planted to form a network of overlapping braced quadrilaterals. This network was triangulated in 1966 and, after a 10-month interval, again in 1967. Throughout the periods of observation...
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Taylor and Francis
1970
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Online Access: | http://nora.nerc.ac.uk/id/eprint/526314/ https://doi.org/10.1179/sre.1970.20.157.322 |
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ftnerc:oai:nora.nerc.ac.uk:526314 2024-01-21T10:01:49+01:00 Survey on moving ice Thomas, R.H. 1970 http://nora.nerc.ac.uk/id/eprint/526314/ https://doi.org/10.1179/sre.1970.20.157.322 unknown Taylor and Francis Thomas, R.H. 1970 Survey on moving ice. Survey Review, 20 (157). 322-338. https://doi.org/10.1179/sre.1970.20.157.322 <https://doi.org/10.1179/sre.1970.20.157.322> Publication - Article PeerReviewed 1970 ftnerc https://doi.org/10.1179/sre.1970.20.157.322 2023-12-22T00:03:08Z In order to measure ice deformation at frequent intervals across the Brunt Ice Shelf, Antarctica, 64 markers were planted to form a network of overlapping braced quadrilaterals. This network was triangulated in 1966 and, after a 10-month interval, again in 1967. Throughout the periods of observation the survey figures suffered continual distortion, and any computation method must allow for this. Making the assumption that ice movement at each marker is linear it is possible to interpolate the positions of observed stations and to process the triangulation scheme as a series of resections. To solve these a computer-oriented resection solution was developed, and adapted to accept measured lengths in addition to angles as input data. In order to correct for Earth-curvature, and to utilise observed true azimuths, a simple spheroid model was adopted. The survey yielded positions of all markers at the times of occupation; position accuracy relative to the origin of the scheme was 1 : 40,000. Values of ice velocity deduced from these positions ranged from 50 metres per year on the grounded inland ice sheet to 350m yr−1 at the front of the floating ice shelf. Article in Journal/Newspaper Antarc* Antarctica Brunt Ice Shelf Ice Sheet Ice Shelf Natural Environment Research Council: NERC Open Research Archive Brunt Ice Shelf ENVELOPE(-22.500,-22.500,-74.750,-74.750) Survey Review 20 157 322 338 |
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Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
In order to measure ice deformation at frequent intervals across the Brunt Ice Shelf, Antarctica, 64 markers were planted to form a network of overlapping braced quadrilaterals. This network was triangulated in 1966 and, after a 10-month interval, again in 1967. Throughout the periods of observation the survey figures suffered continual distortion, and any computation method must allow for this. Making the assumption that ice movement at each marker is linear it is possible to interpolate the positions of observed stations and to process the triangulation scheme as a series of resections. To solve these a computer-oriented resection solution was developed, and adapted to accept measured lengths in addition to angles as input data. In order to correct for Earth-curvature, and to utilise observed true azimuths, a simple spheroid model was adopted. The survey yielded positions of all markers at the times of occupation; position accuracy relative to the origin of the scheme was 1 : 40,000. Values of ice velocity deduced from these positions ranged from 50 metres per year on the grounded inland ice sheet to 350m yr−1 at the front of the floating ice shelf. |
format |
Article in Journal/Newspaper |
author |
Thomas, R.H. |
spellingShingle |
Thomas, R.H. Survey on moving ice |
author_facet |
Thomas, R.H. |
author_sort |
Thomas, R.H. |
title |
Survey on moving ice |
title_short |
Survey on moving ice |
title_full |
Survey on moving ice |
title_fullStr |
Survey on moving ice |
title_full_unstemmed |
Survey on moving ice |
title_sort |
survey on moving ice |
publisher |
Taylor and Francis |
publishDate |
1970 |
url |
http://nora.nerc.ac.uk/id/eprint/526314/ https://doi.org/10.1179/sre.1970.20.157.322 |
long_lat |
ENVELOPE(-22.500,-22.500,-74.750,-74.750) |
geographic |
Brunt Ice Shelf |
geographic_facet |
Brunt Ice Shelf |
genre |
Antarc* Antarctica Brunt Ice Shelf Ice Sheet Ice Shelf |
genre_facet |
Antarc* Antarctica Brunt Ice Shelf Ice Sheet Ice Shelf |
op_relation |
Thomas, R.H. 1970 Survey on moving ice. Survey Review, 20 (157). 322-338. https://doi.org/10.1179/sre.1970.20.157.322 <https://doi.org/10.1179/sre.1970.20.157.322> |
op_doi |
https://doi.org/10.1179/sre.1970.20.157.322 |
container_title |
Survey Review |
container_volume |
20 |
container_issue |
157 |
container_start_page |
322 |
op_container_end_page |
338 |
_version_ |
1788692011427037184 |