Net Balance, Surface Lowering, and Ice-Flow Pattern in the Interior of Lewis Glacier, Mount Kenya, Kenya
Abstract Observations obtained in a long-term monitoring program on Lewis Glacier, Mount Kenya, include measurements of net balance and velocity at a stake network over the period 1978–82, and airborne mapping of the glacier surface topography at the beginning and end of this interval. Horizontal an...
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Language: | English |
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Cambridge University Press (CUP)
1983
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Online Access: | http://dx.doi.org/10.1017/s0022143000030318 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000030318 |
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crcambridgeupr:10.1017/s0022143000030318 2024-03-03T08:46:00+00:00 Net Balance, Surface Lowering, and Ice-Flow Pattern in the Interior of Lewis Glacier, Mount Kenya, Kenya Hastenrath, Stefan 1983 http://dx.doi.org/10.1017/s0022143000030318 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000030318 en eng Cambridge University Press (CUP) Journal of Glaciology volume 29, issue 103, page 392-402 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1983 crcambridgeupr https://doi.org/10.1017/s0022143000030318 2024-02-08T08:41:37Z Abstract Observations obtained in a long-term monitoring program on Lewis Glacier, Mount Kenya, include measurements of net balance and velocity at a stake network over the period 1978–82, and airborne mapping of the glacier surface topography at the beginning and end of this interval. Horizontal and vertical flow components and mass continuity are evaluated along the longitudinal axis of the glacier. The largest horizontal velocity at the surface is about 5 m a −1 , while the submergent vertical velocity at the surface in the upper, and the emergent component in the lower glacier are of the order of 1–2 m a −1 . Horizontal and vertical flow components in the interior of the glacier are calculated from the surface observations under plausible assumptions. Isotachs and streamlines plotted in a longitudinal–vertical cross-section permit the estimation of representative residence times of ice within Lewis Glacier. The largest values for the longest trajectories with submergence at the surface in the uppermost area of the glacier and emergence near the snout are of the order of a few centuries. However, such estimates are compromised, in particular, by the continuing non-equilibrium conditions of Lewis Glacier. Mass continuity is directly related to the vertical motion field. In the upper area of the glacier the submergence velocity exceeds the rise of glacier surface observed with respect to the stake network, while in the lower glacier the emergent flow component falls short of the local negative net balance. This differing behavior of altitudinal zones is consistent with the fact that actual lowering of the glacier surface topography documented by the repeated airborne mappings is larger than expected from the stake network in the upper but less in the lower glacier. This differing behavior of altitude zones appears mitigated by the tendency for confluence in the upper and diffluence in the lower glacier. Article in Journal/Newspaper Journal of Glaciology Lewis Glacier Cambridge University Press Journal of Glaciology 29 103 392 402 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Hastenrath, Stefan Net Balance, Surface Lowering, and Ice-Flow Pattern in the Interior of Lewis Glacier, Mount Kenya, Kenya |
topic_facet |
Earth-Surface Processes |
description |
Abstract Observations obtained in a long-term monitoring program on Lewis Glacier, Mount Kenya, include measurements of net balance and velocity at a stake network over the period 1978–82, and airborne mapping of the glacier surface topography at the beginning and end of this interval. Horizontal and vertical flow components and mass continuity are evaluated along the longitudinal axis of the glacier. The largest horizontal velocity at the surface is about 5 m a −1 , while the submergent vertical velocity at the surface in the upper, and the emergent component in the lower glacier are of the order of 1–2 m a −1 . Horizontal and vertical flow components in the interior of the glacier are calculated from the surface observations under plausible assumptions. Isotachs and streamlines plotted in a longitudinal–vertical cross-section permit the estimation of representative residence times of ice within Lewis Glacier. The largest values for the longest trajectories with submergence at the surface in the uppermost area of the glacier and emergence near the snout are of the order of a few centuries. However, such estimates are compromised, in particular, by the continuing non-equilibrium conditions of Lewis Glacier. Mass continuity is directly related to the vertical motion field. In the upper area of the glacier the submergence velocity exceeds the rise of glacier surface observed with respect to the stake network, while in the lower glacier the emergent flow component falls short of the local negative net balance. This differing behavior of altitudinal zones is consistent with the fact that actual lowering of the glacier surface topography documented by the repeated airborne mappings is larger than expected from the stake network in the upper but less in the lower glacier. This differing behavior of altitude zones appears mitigated by the tendency for confluence in the upper and diffluence in the lower glacier. |
format |
Article in Journal/Newspaper |
author |
Hastenrath, Stefan |
author_facet |
Hastenrath, Stefan |
author_sort |
Hastenrath, Stefan |
title |
Net Balance, Surface Lowering, and Ice-Flow Pattern in the Interior of Lewis Glacier, Mount Kenya, Kenya |
title_short |
Net Balance, Surface Lowering, and Ice-Flow Pattern in the Interior of Lewis Glacier, Mount Kenya, Kenya |
title_full |
Net Balance, Surface Lowering, and Ice-Flow Pattern in the Interior of Lewis Glacier, Mount Kenya, Kenya |
title_fullStr |
Net Balance, Surface Lowering, and Ice-Flow Pattern in the Interior of Lewis Glacier, Mount Kenya, Kenya |
title_full_unstemmed |
Net Balance, Surface Lowering, and Ice-Flow Pattern in the Interior of Lewis Glacier, Mount Kenya, Kenya |
title_sort |
net balance, surface lowering, and ice-flow pattern in the interior of lewis glacier, mount kenya, kenya |
publisher |
Cambridge University Press (CUP) |
publishDate |
1983 |
url |
http://dx.doi.org/10.1017/s0022143000030318 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000030318 |
genre |
Journal of Glaciology Lewis Glacier |
genre_facet |
Journal of Glaciology Lewis Glacier |
op_source |
Journal of Glaciology volume 29, issue 103, page 392-402 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000030318 |
container_title |
Journal of Glaciology |
container_volume |
29 |
container_issue |
103 |
container_start_page |
392 |
op_container_end_page |
402 |
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1792501779323158528 |