Thermo-Physical Characteristics of Glaciers — Toward a Rational Classification
Abstract Forty years ago, Ahlmann considered the thermo-physical character of ice masses as a basis for differentiating glaciers into two broad geophysical groups: (1) polar and (2) temperate . About the same time, Lagally sub-divided glaciers into corresponding thermodynamic categories: (1) kalt an...
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Online Access: | http://dx.doi.org/10.1017/s0022143000031671 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000031671 |
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crcambridgeupr:10.1017/s0022143000031671 2024-03-03T08:42:18+00:00 Thermo-Physical Characteristics of Glaciers — Toward a Rational Classification Miller, Maynard M. 1976 http://dx.doi.org/10.1017/s0022143000031671 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000031671 en eng Cambridge University Press (CUP) Journal of Glaciology volume 16, issue 74, page 297-300 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1976 crcambridgeupr https://doi.org/10.1017/s0022143000031671 2024-02-08T08:40:23Z Abstract Forty years ago, Ahlmann considered the thermo-physical character of ice masses as a basis for differentiating glaciers into two broad geophysical groups: (1) polar and (2) temperate . About the same time, Lagally sub-divided glaciers into corresponding thermodynamic categories: (1) kalt and (2) warmen . By this it was understood that the temperature of a polar, or “cold”, glacier was perennially sub-freezing throughout, except for a shallow surface zone which might be warmed for a few centimeters each year by seasonal atmospheric variations. Conversely, in a temperate, or “warm”, glacier, the temperature below a recurring winter chill layer was consistently at the pressure melting point. As these terms are thermodynamic in connotation, glaciers of the polar type may exist at relatively low altitudes if their elevations are sufficiently great. Temperate glaciers may be found even above the Arctic Circle at elevations low enough that chilling conditions are not induced by the lapse rate. In these distinctions, it is implied that regardless of geographical location a glacier’s mean internal temperature represents an identifiable characteristic which can be shown critically to affect the mass and liquid balance of ice masses and significantly to relate climatic influences to glacier regimes. The importance of these implications, and the fact that they are based on a gross, sometimes changing, and always difficult to measure, thermo-physical characteristic, makes some explicit terminology desirable. To some extent Ahlmann addressed this problem by introducing a subordinate classification, sub-polar glaciers. In these, the penetration of seasonal warmth involved only a shallow surface layer at 0°C, but still to a depth substantially greater than the superficial warming experienced in summer on polar glaciers. Lagally also recognized an intermediate type which he called “transitional”, characterized by a relatively deep penetration of 0°C englacial conditions during the summer. These pioneering efforts ... Article in Journal/Newspaper Arctic Journal of Glaciology Cambridge University Press Arctic Ahlmann ENVELOPE(-65.750,-65.750,-67.867,-67.867) Lagally ENVELOPE(-67.093,-67.093,-67.146,-67.146) Journal of Glaciology 16 74 297 300 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Miller, Maynard M. Thermo-Physical Characteristics of Glaciers — Toward a Rational Classification |
topic_facet |
Earth-Surface Processes |
description |
Abstract Forty years ago, Ahlmann considered the thermo-physical character of ice masses as a basis for differentiating glaciers into two broad geophysical groups: (1) polar and (2) temperate . About the same time, Lagally sub-divided glaciers into corresponding thermodynamic categories: (1) kalt and (2) warmen . By this it was understood that the temperature of a polar, or “cold”, glacier was perennially sub-freezing throughout, except for a shallow surface zone which might be warmed for a few centimeters each year by seasonal atmospheric variations. Conversely, in a temperate, or “warm”, glacier, the temperature below a recurring winter chill layer was consistently at the pressure melting point. As these terms are thermodynamic in connotation, glaciers of the polar type may exist at relatively low altitudes if their elevations are sufficiently great. Temperate glaciers may be found even above the Arctic Circle at elevations low enough that chilling conditions are not induced by the lapse rate. In these distinctions, it is implied that regardless of geographical location a glacier’s mean internal temperature represents an identifiable characteristic which can be shown critically to affect the mass and liquid balance of ice masses and significantly to relate climatic influences to glacier regimes. The importance of these implications, and the fact that they are based on a gross, sometimes changing, and always difficult to measure, thermo-physical characteristic, makes some explicit terminology desirable. To some extent Ahlmann addressed this problem by introducing a subordinate classification, sub-polar glaciers. In these, the penetration of seasonal warmth involved only a shallow surface layer at 0°C, but still to a depth substantially greater than the superficial warming experienced in summer on polar glaciers. Lagally also recognized an intermediate type which he called “transitional”, characterized by a relatively deep penetration of 0°C englacial conditions during the summer. These pioneering efforts ... |
format |
Article in Journal/Newspaper |
author |
Miller, Maynard M. |
author_facet |
Miller, Maynard M. |
author_sort |
Miller, Maynard M. |
title |
Thermo-Physical Characteristics of Glaciers — Toward a Rational Classification |
title_short |
Thermo-Physical Characteristics of Glaciers — Toward a Rational Classification |
title_full |
Thermo-Physical Characteristics of Glaciers — Toward a Rational Classification |
title_fullStr |
Thermo-Physical Characteristics of Glaciers — Toward a Rational Classification |
title_full_unstemmed |
Thermo-Physical Characteristics of Glaciers — Toward a Rational Classification |
title_sort |
thermo-physical characteristics of glaciers — toward a rational classification |
publisher |
Cambridge University Press (CUP) |
publishDate |
1976 |
url |
http://dx.doi.org/10.1017/s0022143000031671 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000031671 |
long_lat |
ENVELOPE(-65.750,-65.750,-67.867,-67.867) ENVELOPE(-67.093,-67.093,-67.146,-67.146) |
geographic |
Arctic Ahlmann Lagally |
geographic_facet |
Arctic Ahlmann Lagally |
genre |
Arctic Journal of Glaciology |
genre_facet |
Arctic Journal of Glaciology |
op_source |
Journal of Glaciology volume 16, issue 74, page 297-300 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000031671 |
container_title |
Journal of Glaciology |
container_volume |
16 |
container_issue |
74 |
container_start_page |
297 |
op_container_end_page |
300 |
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1792497725258858496 |