Do subglacial bedforms comprise a size and shape continuum?

Jeremy C. Ely; Chris D. Clark; Matteo Spagnolo; Chris R. Stokes; Sarah L. Greenwood; Anna L. C. Hughes; Paul Dunlop; Dale Hess

doi:10.1016/j.geomorph.2016.01.001

Do subglacial bedforms comprise a size and shape continuum?

Jeremy C. Ely^*, Chris D. Clark, Matteo Spagnolo, Chris R. Stokes, Sarah L. Greenwood, Anna L. C. Hughes, Paul Dunlop, Dale Hess

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

82 Citations (Scopus)

12 Downloads (Pure)

Abstract

Understanding the evolution of the ice-bed interface is fundamentally important for gaining insight into the dynamics of ice masses and how subglacial landforms are created. However, the formation of the suite of landforms generated at this boundary - subglacial bedforms - is a contentious issue that is yet to be fully resolved. Bedforms formed in aeolian, fluvial, and marine environments either belong to separate morphological populations or are thought to represent a continuum of forms generated by the same governing processes. For subglacial bedforms, a size and shape continuum has been hypothesised, yet it has not been fully tested. Here we analyse the largest data set of subglacial bedform size and shape measurements ever collated (96,900 bedforms). Our results show that flutes form a distinct population of narrow bedforms. However, no clear distinction was found between drumlins and megascale glacial lineations (MSGLs), which form a continuum of subglacial lineations. A continuum of subglacial ribs also exists, with no clear size or shape distinctions indicating separate populations. Furthermore, an underreported class of bedform with no clear orientation to ice flow (quasi-circular bedforms) overlaps with the ribbed and lineation continua and typically occurs in spatial transition zones between the two, potentially merging these three bedform types into a larger continuum.

Original language	English
Pages (from-to)	108-119
Number of pages	12
Journal	Geomorphology
Volume	257
Early online date	6 Jan 2016
DOIs	https://doi.org/10.1016/j.geomorph.2016.01.001
Publication status	Published - 15 Mar 2016

Bibliographical note

The authors thank R.D. Larter, M. Ross, 2 anonymous reviewers, and the editor for their useful comments which improved this manuscript. J.C.E. thanks Kathy and Chris Denison for funding his PhD. This work was initiated and supported by a NERC grant (NE/D011175/1) to C.D.C. M.S. was supported by a NERC new investigator grant (NE/J004766/1) and C.R.S., a Philip Leverhulme Prize. S.L.G. acknowledges the University of Sheffield, the Swedish Research Council, and Linnaeus grants to Johan Kleman and the Bolin Centre for Climate Research. A.L.C.H acknowledges BGS NERC PhD studentship (NE/S/A/2004/12102). We thank Andrew Fowler and Richard Hindmarsh for fruitful discussions.

Keywords

Drumlins
Flutes
Ribbed moraine
Subglacial bedforms

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1016/j.geomorph.2016.01.001Licence: CC BY

Do subglacial bedforms comprise a size and shape continuum?
Crown Copyright © 2016 Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Final published version, 2.39 MBLicence: CC BY

Cite this

@article{b915b19dfa0949a6b4dab3a90f418afb,

title = "Do subglacial bedforms comprise a size and shape continuum?",

abstract = "Understanding the evolution of the ice-bed interface is fundamentally important for gaining insight into the dynamics of ice masses and how subglacial landforms are created. However, the formation of the suite of landforms generated at this boundary - subglacial bedforms - is a contentious issue that is yet to be fully resolved. Bedforms formed in aeolian, fluvial, and marine environments either belong to separate morphological populations or are thought to represent a continuum of forms generated by the same governing processes. For subglacial bedforms, a size and shape continuum has been hypothesised, yet it has not been fully tested. Here we analyse the largest data set of subglacial bedform size and shape measurements ever collated (96,900 bedforms). Our results show that flutes form a distinct population of narrow bedforms. However, no clear distinction was found between drumlins and megascale glacial lineations (MSGLs), which form a continuum of subglacial lineations. A continuum of subglacial ribs also exists, with no clear size or shape distinctions indicating separate populations. Furthermore, an underreported class of bedform with no clear orientation to ice flow (quasi-circular bedforms) overlaps with the ribbed and lineation continua and typically occurs in spatial transition zones between the two, potentially merging these three bedform types into a larger continuum.",

keywords = "Drumlins, Flutes, Ribbed moraine, Subglacial bedforms",

author = "Ely, {Jeremy C.} and Clark, {Chris D.} and Matteo Spagnolo and Stokes, {Chris R.} and Greenwood, {Sarah L.} and Hughes, {Anna L. C.} and Paul Dunlop and Dale Hess",

note = "The authors thank R.D. Larter, M. Ross, 2 anonymous reviewers, and the editor for their useful comments which improved this manuscript. J.C.E. thanks Kathy and Chris Denison for funding his PhD. This work was initiated and supported by a NERC grant (NE/D011175/1) to C.D.C. M.S. was supported by a NERC new investigator grant (NE/J004766/1) and C.R.S., a Philip Leverhulme Prize. S.L.G. acknowledges the University of Sheffield, the Swedish Research Council, and Linnaeus grants to Johan Kleman and the Bolin Centre for Climate Research. A.L.C.H acknowledges BGS NERC PhD studentship (NE/S/A/2004/12102). We thank Andrew Fowler and Richard Hindmarsh for fruitful discussions.",

year = "2016",

month = mar,

day = "15",

doi = "10.1016/j.geomorph.2016.01.001",

language = "English",

volume = "257",

pages = "108--119",

journal = "Geomorphology",