Tabular Icebergs: Implications from Geophysical Studies of Ice Shelves
Abstract Recent geophysical and glaciological investigations of the Ross Ice Shelf have revealed many complexities in the ice shelf that can be important factors in iceberg structure. The presence of rift zones, surface and bottom crevasses, corrugations, ridge/troughs, and other features could subs...
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Cambridge University Press (CUP)
1982
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Online Access: | http://dx.doi.org/10.1017/s0022143000005037 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000005037 |
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crcambridgeupr:10.1017/s0022143000005037 2024-03-03T08:45:29+00:00 Tabular Icebergs: Implications from Geophysical Studies of Ice Shelves Shabtaie, Sion Bentley, Charles R. 1982 http://dx.doi.org/10.1017/s0022143000005037 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000005037 en eng Cambridge University Press (CUP) Journal of Glaciology volume 28, issue 100, page 413-430 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1982 crcambridgeupr https://doi.org/10.1017/s0022143000005037 2024-02-08T08:39:08Z Abstract Recent geophysical and glaciological investigations of the Ross Ice Shelf have revealed many complexities in the ice shelf that can be important factors in iceberg structure. The presence of rift zones, surface and bottom crevasses, corrugations, ridge/troughs, and other features could substantially modify the hydraulics of iceberg towing and lead to disintegration in the course of transport. The relationships between the elevation above sea-level and total ice thickness for three ice shelves (Ross, Brunt, and McMurdo) are given; from them, expressions for the thickness/freeboard ratios of tabular icebergs calved from these ice shelves are obtained. The relationships obtained from the measured values of surface elevation and ice thickness are in agreement with models derived assuming hydrostatic equilibrium. Areas of brine infiltration into the Ross Ice Shelf have been mapped. Examples of radar profiles in these zones are shown. Absorption from the brine layers results in a poor or absent bottom echo. It is probable that little saline ice exists at the bottom of the Ross Ice Shelf front due to a rapid bottom melting near the ice front, and that the thickness of the saline ice at the bottom of icebergs calving from the Ross Ice Shelf is no more than a few meters, if there is any at all. We have observed many rift zones on the ice shelf by airborne radar techniques, and at one site the bottom and surface topographies of (buried) rift zones have been delineated. These rift zones play an obvious role in iceberg formation and may also affect the dynamics of iceberg transport. Bottom crevasses with different shapes, sizes, and spacings are abundant in ice shelves; probably some are filled with saline ice and others with unfrozen sea-water. Existence of these bottom crevasses could lead to a rapid disintegration of icebergs in the course of transport, as well as increasing the frictional drag at the ice-water boundary. Radar profiles of the ice shelf front at four sites in flow bands of very different ... Article in Journal/Newspaper Ice Shelf Ice Shelves Journal of Glaciology Ross Ice Shelf Cambridge University Press Ross Ice Shelf Journal of Glaciology 28 100 413 430 |
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Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Shabtaie, Sion Bentley, Charles R. Tabular Icebergs: Implications from Geophysical Studies of Ice Shelves |
topic_facet |
Earth-Surface Processes |
description |
Abstract Recent geophysical and glaciological investigations of the Ross Ice Shelf have revealed many complexities in the ice shelf that can be important factors in iceberg structure. The presence of rift zones, surface and bottom crevasses, corrugations, ridge/troughs, and other features could substantially modify the hydraulics of iceberg towing and lead to disintegration in the course of transport. The relationships between the elevation above sea-level and total ice thickness for three ice shelves (Ross, Brunt, and McMurdo) are given; from them, expressions for the thickness/freeboard ratios of tabular icebergs calved from these ice shelves are obtained. The relationships obtained from the measured values of surface elevation and ice thickness are in agreement with models derived assuming hydrostatic equilibrium. Areas of brine infiltration into the Ross Ice Shelf have been mapped. Examples of radar profiles in these zones are shown. Absorption from the brine layers results in a poor or absent bottom echo. It is probable that little saline ice exists at the bottom of the Ross Ice Shelf front due to a rapid bottom melting near the ice front, and that the thickness of the saline ice at the bottom of icebergs calving from the Ross Ice Shelf is no more than a few meters, if there is any at all. We have observed many rift zones on the ice shelf by airborne radar techniques, and at one site the bottom and surface topographies of (buried) rift zones have been delineated. These rift zones play an obvious role in iceberg formation and may also affect the dynamics of iceberg transport. Bottom crevasses with different shapes, sizes, and spacings are abundant in ice shelves; probably some are filled with saline ice and others with unfrozen sea-water. Existence of these bottom crevasses could lead to a rapid disintegration of icebergs in the course of transport, as well as increasing the frictional drag at the ice-water boundary. Radar profiles of the ice shelf front at four sites in flow bands of very different ... |
format |
Article in Journal/Newspaper |
author |
Shabtaie, Sion Bentley, Charles R. |
author_facet |
Shabtaie, Sion Bentley, Charles R. |
author_sort |
Shabtaie, Sion |
title |
Tabular Icebergs: Implications from Geophysical Studies of Ice Shelves |
title_short |
Tabular Icebergs: Implications from Geophysical Studies of Ice Shelves |
title_full |
Tabular Icebergs: Implications from Geophysical Studies of Ice Shelves |
title_fullStr |
Tabular Icebergs: Implications from Geophysical Studies of Ice Shelves |
title_full_unstemmed |
Tabular Icebergs: Implications from Geophysical Studies of Ice Shelves |
title_sort |
tabular icebergs: implications from geophysical studies of ice shelves |
publisher |
Cambridge University Press (CUP) |
publishDate |
1982 |
url |
http://dx.doi.org/10.1017/s0022143000005037 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000005037 |
geographic |
Ross Ice Shelf |
geographic_facet |
Ross Ice Shelf |
genre |
Ice Shelf Ice Shelves Journal of Glaciology Ross Ice Shelf |
genre_facet |
Ice Shelf Ice Shelves Journal of Glaciology Ross Ice Shelf |
op_source |
Journal of Glaciology volume 28, issue 100, page 413-430 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000005037 |
container_title |
Journal of Glaciology |
container_volume |
28 |
container_issue |
100 |
container_start_page |
413 |
op_container_end_page |
430 |
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1792501043462930432 |