Surging Glaciers—The Dilemma Continues
Abstract A glacier surge, according to most definitions, is a short-lived phase of unusually rapid glacier flow, after which the glacier returns to more normal behavior, with the surge–non-surge phases recurring on a regular or periodic basis. Recent interest is largely directed toward analyzing the...
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1979
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Online Access: | http://dx.doi.org/10.1017/s0022143000015112 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015112 |
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crcambridgeupr:10.1017/s0022143000015112 2024-03-03T08:46:00+00:00 Surging Glaciers—The Dilemma Continues Meier, M. F. 1979 http://dx.doi.org/10.1017/s0022143000015112 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015112 en eng Cambridge University Press (CUP) Journal of Glaciology volume 24, issue 90, page 502-503 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1979 crcambridgeupr https://doi.org/10.1017/s0022143000015112 2024-02-08T08:47:47Z Abstract A glacier surge, according to most definitions, is a short-lived phase of unusually rapid glacier flow, after which the glacier returns to more normal behavior, with the surge–non-surge phases recurring on a regular or periodic basis. Recent interest is largely directed toward analyzing the effect of water at the bed on the periodic change in flow regime and on the rapid flow during a surge phase. For instance, study of a local depression of basal shear stress that dependson a “friction lubrication factor” which becomes important as the ice velocity increases, is one promising phenomenological approach. An important physical approach focuses on a water “collection zone” that occurs where and when the longitudinal pressure gradient in the subglacial wtaer film approaches zero. The data necessary for properly verifying these and other similar theories do not yet exist. Computer modeling of rapidly-surging glaciers based on a “friction lubrication factor” has been quite successful in duplicating their major features. Once rapid movement (10 2 –10 3 m a –1 ) has begun, sufficient water is generated at the bed, from ice melted by heat dissipated in sliding, to produce some decoupling of the glacier from its bed and to maintain the surge, but only if this water is not lost by rapid drainage. Some glaciers exhibit periodic pulses in which the basal sliding velocity during the fastest part of the pulses appears to be in the range for “normal” glaciers (<10 2 m a –1 ). Some evidence suggests a continuum of behavior from steady (normal) glaciers through these “mini-surges” to classic surges. This continuum and the “mini-surges” seem to be difficult to explain quantitatively by existing theories. A few glaciers flow continuously at surging speeds (>10 3 m a –1 ) in certain reaches. The up-glacier transition reaches show speeds decreasing to “nonrmal” with no indication of intermediate surging regime, but the down-glacier transition reaches may be areas where surges are triggered. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 24 90 502 503 |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
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Earth-Surface Processes Meier, M. F. Surging Glaciers—The Dilemma Continues |
topic_facet |
Earth-Surface Processes |
description |
Abstract A glacier surge, according to most definitions, is a short-lived phase of unusually rapid glacier flow, after which the glacier returns to more normal behavior, with the surge–non-surge phases recurring on a regular or periodic basis. Recent interest is largely directed toward analyzing the effect of water at the bed on the periodic change in flow regime and on the rapid flow during a surge phase. For instance, study of a local depression of basal shear stress that dependson a “friction lubrication factor” which becomes important as the ice velocity increases, is one promising phenomenological approach. An important physical approach focuses on a water “collection zone” that occurs where and when the longitudinal pressure gradient in the subglacial wtaer film approaches zero. The data necessary for properly verifying these and other similar theories do not yet exist. Computer modeling of rapidly-surging glaciers based on a “friction lubrication factor” has been quite successful in duplicating their major features. Once rapid movement (10 2 –10 3 m a –1 ) has begun, sufficient water is generated at the bed, from ice melted by heat dissipated in sliding, to produce some decoupling of the glacier from its bed and to maintain the surge, but only if this water is not lost by rapid drainage. Some glaciers exhibit periodic pulses in which the basal sliding velocity during the fastest part of the pulses appears to be in the range for “normal” glaciers (<10 2 m a –1 ). Some evidence suggests a continuum of behavior from steady (normal) glaciers through these “mini-surges” to classic surges. This continuum and the “mini-surges” seem to be difficult to explain quantitatively by existing theories. A few glaciers flow continuously at surging speeds (>10 3 m a –1 ) in certain reaches. The up-glacier transition reaches show speeds decreasing to “nonrmal” with no indication of intermediate surging regime, but the down-glacier transition reaches may be areas where surges are triggered. |
format |
Article in Journal/Newspaper |
author |
Meier, M. F. |
author_facet |
Meier, M. F. |
author_sort |
Meier, M. F. |
title |
Surging Glaciers—The Dilemma Continues |
title_short |
Surging Glaciers—The Dilemma Continues |
title_full |
Surging Glaciers—The Dilemma Continues |
title_fullStr |
Surging Glaciers—The Dilemma Continues |
title_full_unstemmed |
Surging Glaciers—The Dilemma Continues |
title_sort |
surging glaciers—the dilemma continues |
publisher |
Cambridge University Press (CUP) |
publishDate |
1979 |
url |
http://dx.doi.org/10.1017/s0022143000015112 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015112 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 24, issue 90, page 502-503 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000015112 |
container_title |
Journal of Glaciology |
container_volume |
24 |
container_issue |
90 |
container_start_page |
502 |
op_container_end_page |
503 |
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1792501794331426816 |