Experimental determination of a double-valued drag relationship for glacier sliding

dc.contributor.author Zoet, Lucas
dc.contributor.author Iverson, Neal
dc.contributor.author Iverson, Neal
dc.contributor.department Geological and Atmospheric Sciences
dc.date 2018-02-18T09:28:09.000
dc.date.accessioned 2020-06-30T04:03:27Z
dc.date.available 2020-06-30T04:03:27Z
dc.date.copyright Thu Jan 01 00:00:00 UTC 2015
dc.date.issued 2015-02-01
dc.description.abstract <p>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.</p>
dc.description.comments <p>This article is from <em>Journal of Glaciology </em>61 (2015): 1, doi:<a href="http://dx.doi.org/10.3189/2015JoG14J174" target="_blank">10.3189/2015JoG14J174</a>. Posted with permission.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/ge_at_pubs/152/
dc.identifier.articleid 1135
dc.identifier.contextkey 10068446
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath ge_at_pubs/152
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/38084
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/ge_at_pubs/152/2015_Iverson_ExperimentalDetermination.pdf|||Fri Jan 14 20:37:20 UTC 2022
dc.source.uri 10.3189/2015JoG14J174
dc.subject.disciplines Geomorphology
dc.subject.disciplines Glaciology
dc.subject.keywords basal ice
dc.subject.keywords glacier flow
dc.subject.keywords glacier mechanics
dc.subject.keywords glacier modelling
dc.subject.keywords subglacial processes
dc.title Experimental determination of a double-valued drag relationship for glacier sliding
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isAuthorOfPublication 8f9617fd-0ee4-4473-b7bb-ef722542e676
relation.isOrgUnitOfPublication 29272786-4c4a-4d63-98d6-e7b6d6730c45
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