Channelization of plumes beneath ice shelves

M. C. Dallaston, I. J. Hewitt, A. J. Wells

Research output: Contribution to journalArticle

8 Citations (Scopus)
17 Downloads (Pure)

Abstract

We study a simplified model of ice-ocean interaction beneath a floating ice shelf, and investigate the possibility for channels to form in the ice shelf base due to spatial variations in conditions at the grounding line. The model combines an extensional thin-film description of viscous ice flow in the shelf, with melting at its base driven by a turbulent ocean plume. Small transverse perturbations to the one-dimensional steady state are considered, driven either by ice thickness or subglacial discharge variations across the grounding line. Either forcing leads to the growth of channels downstream, with melting driven by locally enhanced ocean velocities, and thus heat transfer. Narrow channels are smoothed out due to turbulent mixing in the ocean plume, leading to a preferred wavelength for channel growth. In the absence of perturbations at the grounding line, linear stability analysis suggests that the one-dimensional state is stable to initial perturbations, chiefly due to the background ice advection.

Original languageEnglish
Pages (from-to)109-134
Number of pages26
JournalJournal of Fluid Mechanics
Volume785
DOIs
Publication statusPublished - 11 Nov 2015
Externally publishedYes

Keywords

  • geophysical and geological flows
  • ice sheets
  • morphological instability

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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  • Cite this

    Dallaston, M. C., Hewitt, I. J., & Wells, A. J. (2015). Channelization of plumes beneath ice shelves. Journal of Fluid Mechanics, 785, 109-134. https://doi.org/10.1017/jfm.2015.609