Experimental determination of a double-valued drag relationship for glacier sliding
ABSTRACT. The contribution of glaciers to sea-level rise and their effects on landscape evolution depend on the poorly known relationship between sliding speed and drag at the ice/bed interface. Results from experiments with a new rotary laboratory device demonstrate empirically for the first time a...
Main Authors: | , |
---|---|
Other Authors: | |
Format: | Text |
Language: | English |
Subjects: | |
Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.680.3974 http://www.igsoc.org/journal/61/225/j14j174.pdf |
id |
ftciteseerx:oai:CiteSeerX.psu:10.1.1.680.3974 |
---|---|
record_format |
openpolar |
spelling |
ftciteseerx:oai:CiteSeerX.psu:10.1.1.680.3974 2023-05-15T16:41:03+02:00 Experimental determination of a double-valued drag relationship for glacier sliding Lucas K. Zoet Neal R. Iverson The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.680.3974 http://www.igsoc.org/journal/61/225/j14j174.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.680.3974 http://www.igsoc.org/journal/61/225/j14j174.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.igsoc.org/journal/61/225/j14j174.pdf basal ice glacier flow glacier mechanics glacier modelling subglacial processes text ftciteseerx 2016-01-08T17:51:50Z ABSTRACT. The contribution of glaciers to sea-level rise and their effects on landscape evolution depend on the poorly known relationship between sliding speed and drag at the ice/bed interface. Results from experiments with a new rotary laboratory device demonstrate empirically for the first time a double-valued drag relationship like that suggested by some sliding theories: steady drag on a rigid, sinusoidal bed increases, peaks and declines at progressively higher sliding speeds due to growth of cavities in the lee sides of bed undulations. Drag decreases with increased sliding speed if cavities extend beyond the inflection points of up-glacier facing surfaces, so that adverse bed slopes in contact with ice diminish with further cavity growth. These results indicate that shear tractions on glacier beds can potentially decrease due to increases in sliding speed driven by weather or climate variability, promoting even more rapid glacier motion by requiring greater strain rates to produce resistive stresses. Although a double-valued drag relationship has not yet been demonstrated for the complicated geometries of real glacier beds, both its potential major implications and the characteristically convex stoss surfaces of bumps on real glacier beds provide stimulus for exploring the effects of this relationship in ice-sheet models. Text Ice Sheet Unknown |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
ftciteseerx |
language |
English |
topic |
basal ice glacier flow glacier mechanics glacier modelling subglacial processes |
spellingShingle |
basal ice glacier flow glacier mechanics glacier modelling subglacial processes Lucas K. Zoet Neal R. Iverson Experimental determination of a double-valued drag relationship for glacier sliding |
topic_facet |
basal ice glacier flow glacier mechanics glacier modelling subglacial processes |
description |
ABSTRACT. The contribution of glaciers to sea-level rise and their effects on landscape evolution depend on the poorly known relationship between sliding speed and drag at the ice/bed interface. Results from experiments with a new rotary laboratory device demonstrate empirically for the first time a double-valued drag relationship like that suggested by some sliding theories: steady drag on a rigid, sinusoidal bed increases, peaks and declines at progressively higher sliding speeds due to growth of cavities in the lee sides of bed undulations. Drag decreases with increased sliding speed if cavities extend beyond the inflection points of up-glacier facing surfaces, so that adverse bed slopes in contact with ice diminish with further cavity growth. These results indicate that shear tractions on glacier beds can potentially decrease due to increases in sliding speed driven by weather or climate variability, promoting even more rapid glacier motion by requiring greater strain rates to produce resistive stresses. Although a double-valued drag relationship has not yet been demonstrated for the complicated geometries of real glacier beds, both its potential major implications and the characteristically convex stoss surfaces of bumps on real glacier beds provide stimulus for exploring the effects of this relationship in ice-sheet models. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Lucas K. Zoet Neal R. Iverson |
author_facet |
Lucas K. Zoet Neal R. Iverson |
author_sort |
Lucas K. Zoet |
title |
Experimental determination of a double-valued drag relationship for glacier sliding |
title_short |
Experimental determination of a double-valued drag relationship for glacier sliding |
title_full |
Experimental determination of a double-valued drag relationship for glacier sliding |
title_fullStr |
Experimental determination of a double-valued drag relationship for glacier sliding |
title_full_unstemmed |
Experimental determination of a double-valued drag relationship for glacier sliding |
title_sort |
experimental determination of a double-valued drag relationship for glacier sliding |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.680.3974 http://www.igsoc.org/journal/61/225/j14j174.pdf |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
http://www.igsoc.org/journal/61/225/j14j174.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.680.3974 http://www.igsoc.org/journal/61/225/j14j174.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766031495865040896 |