Intra-seasonal changes in deformation profiles revealed by borehole studies, Storglaciären, Sweden
Abstract In 1985, 1987 and 1988, we measured deformation of boreholes in the ablation zone of Storglaciären. A different hole was used each year. Deformation profiles were determined for four consecutive time periods between mid-July and early September. All three holes were in an area where the gla...
Published in: | Journal of Glaciology |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Cambridge University Press (CUP)
1992
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1017/s0022143000002239 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000002239 |
id |
crcambridgeupr:10.1017/s0022143000002239 |
---|---|
record_format |
openpolar |
spelling |
crcambridgeupr:10.1017/s0022143000002239 2024-03-03T08:46:08+00:00 Intra-seasonal changes in deformation profiles revealed by borehole studies, Storglaciären, Sweden Hooke, Roger LeB. Pohjola, Veijo Allan Jansson, Peter Kohler, Jack 1992 http://dx.doi.org/10.1017/s0022143000002239 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000002239 en eng Cambridge University Press (CUP) Journal of Glaciology volume 38, issue 130, page 348-358 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1992 crcambridgeupr https://doi.org/10.1017/s0022143000002239 2024-02-08T08:39:08Z Abstract In 1985, 1987 and 1988, we measured deformation of boreholes in the ablation zone of Storglaciären. A different hole was used each year. Deformation profiles were determined for four consecutive time periods between mid-July and early September. All three holes were in an area where the glacier lies in an overdeepened part of the bed, up-glacier from a riegel. The first hole was approximately on the glacier center line while the others were midway between the center line and one or the other margin. Despite large standard errors, variations in the deformation profiles during the melt season are broadly consistent with other data. We thus believe that they are real, and that they reflect changes in the stress field resulting from changes in drag at the bed. A decrease in drag early in the melt season, coupled with convergence of the bed contours towards the riegel, is believed to be responsible for a previously documented increase in vertical velocity just up glacier from the riegal at this time of year. Also noteworthy, but perhaps problematical, was an abrupt transverse shear of at a depth of ~25 m near the center of the glacier in July 1985. The shear took place in the zone in which cold ice near the surface gives way to temperate ice deeper in the glacier. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Storglaciären ENVELOPE(18.560,18.560,67.904,67.904) Journal of Glaciology 38 130 348 358 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Hooke, Roger LeB. Pohjola, Veijo Allan Jansson, Peter Kohler, Jack Intra-seasonal changes in deformation profiles revealed by borehole studies, Storglaciären, Sweden |
topic_facet |
Earth-Surface Processes |
description |
Abstract In 1985, 1987 and 1988, we measured deformation of boreholes in the ablation zone of Storglaciären. A different hole was used each year. Deformation profiles were determined for four consecutive time periods between mid-July and early September. All three holes were in an area where the glacier lies in an overdeepened part of the bed, up-glacier from a riegel. The first hole was approximately on the glacier center line while the others were midway between the center line and one or the other margin. Despite large standard errors, variations in the deformation profiles during the melt season are broadly consistent with other data. We thus believe that they are real, and that they reflect changes in the stress field resulting from changes in drag at the bed. A decrease in drag early in the melt season, coupled with convergence of the bed contours towards the riegel, is believed to be responsible for a previously documented increase in vertical velocity just up glacier from the riegal at this time of year. Also noteworthy, but perhaps problematical, was an abrupt transverse shear of at a depth of ~25 m near the center of the glacier in July 1985. The shear took place in the zone in which cold ice near the surface gives way to temperate ice deeper in the glacier. |
format |
Article in Journal/Newspaper |
author |
Hooke, Roger LeB. Pohjola, Veijo Allan Jansson, Peter Kohler, Jack |
author_facet |
Hooke, Roger LeB. Pohjola, Veijo Allan Jansson, Peter Kohler, Jack |
author_sort |
Hooke, Roger LeB. |
title |
Intra-seasonal changes in deformation profiles revealed by borehole studies, Storglaciären, Sweden |
title_short |
Intra-seasonal changes in deformation profiles revealed by borehole studies, Storglaciären, Sweden |
title_full |
Intra-seasonal changes in deformation profiles revealed by borehole studies, Storglaciären, Sweden |
title_fullStr |
Intra-seasonal changes in deformation profiles revealed by borehole studies, Storglaciären, Sweden |
title_full_unstemmed |
Intra-seasonal changes in deformation profiles revealed by borehole studies, Storglaciären, Sweden |
title_sort |
intra-seasonal changes in deformation profiles revealed by borehole studies, storglaciären, sweden |
publisher |
Cambridge University Press (CUP) |
publishDate |
1992 |
url |
http://dx.doi.org/10.1017/s0022143000002239 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000002239 |
long_lat |
ENVELOPE(18.560,18.560,67.904,67.904) |
geographic |
Storglaciären |
geographic_facet |
Storglaciären |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 38, issue 130, page 348-358 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000002239 |
container_title |
Journal of Glaciology |
container_volume |
38 |
container_issue |
130 |
container_start_page |
348 |
op_container_end_page |
358 |
_version_ |
1792502050320285696 |