Skip to main content

Research Repository

Advanced Search

Subglacial bedform morphology controlled by ice speed and sediment thickness

Barchyn, T.E.; Dowling, T.P.F.; Stokes, C.R.; Hugenholtz, C.G.

Subglacial bedform morphology controlled by ice speed and sediment thickness Thumbnail


Authors

T.E. Barchyn

T.P.F. Dowling

C.G. Hugenholtz



Abstract

Subglacial bedforms (drumlins, ribbed moraines, mega-scale glacial lineations) are enigmatic repetitive flow-parallel and flow-transverse landforms common in glaciated landscapes. Their evolution and morphology are a potentially powerful constraint for ice sheet modelling, but there is little consensus on bedform dynamics or formative mechanisms. Here we explore shallow sediment bedform dynamics via a simple model that iterates: (i) down-flow till flux, (ii) pressure gradient driven till flux, and (iii) entrainment and deposition of sediment. Under various boundary conditions, replicas of subglacial bedforms readily emerge. Bedform dynamics mirror those in subaqueous and aeolian domains. Transitions between ribbed moraines and elongate flow-parallel bedforms are associated with increasing ice speeds and declining sediment thickness. These simulations provide quantitative flux estimates and suggest that widely observed transitions in shallow sediment subglacial bedforms (e.g., ribbed moraines to drumlinoids to mega-scale glacial lineations) are manifestations of subtle variations in ice velocity and sediment thickness.

Citation

Barchyn, T., Dowling, T., Stokes, C., & Hugenholtz, C. (2016). Subglacial bedform morphology controlled by ice speed and sediment thickness. Geophysical Research Letters, 43(14), 7572-7580. https://doi.org/10.1002/2016gl069558

Journal Article Type Article
Acceptance Date Jul 8, 2016
Online Publication Date Jul 30, 2016
Publication Date Jul 30, 2016
Deposit Date Jul 14, 2016
Publicly Available Date Jan 30, 2017
Journal Geophysical Research Letters
Print ISSN 0094-8276
Electronic ISSN 1944-8007
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 43
Issue 14
Pages 7572-7580
DOI https://doi.org/10.1002/2016gl069558
Public URL https://durham-repository.worktribe.com/output/1400869

Files

Published Journal Article (2.6 Mb)
PDF

Copyright Statement
Thomas E. Barchyn, Thomas P. F. Dowling, Chris R. Stokes, Chris H. Hugenholtz (2016), Subglacial bedform morphology controlled by ice speed and sediment thickness, Geophysical research letters, 43(14): 7572-7580, 10.1002/2016GL069558 (DOI). To view the published open abstract, go to http://dx.doi.org and enter the DOI.






You might also like



Downloadable Citations