Deformation of till beneath ice stream B, West Antarctica

Richard B. Alley, D. D. Blankenship, C. R. Bentley, S. T. Rooney

Research output: Contribution to journalArticle

391 Citations (Scopus)

Abstract

The behaviour and possible instability of the West Antarctic ice sheet depend fundamentally on the dynamics of the large ice streams which drain it. Model calculations show that most ice-stream velocity arises at the bed 1,2, and radar sounding has shown the bed to be wet3, but the basal boundary condition is not well understood. Seismic evidence from the Upstream B camp (UpB) on the Siple Coast of West Antarctica4 shows that the ice stream there rests on a layer of unconsolidated sediment averaging 5 or 6 m thick, in which the water pressure is only ∼50 kPa less than the overburden pressure. Because this thin layer occurs well inland beneath an active ice sheet and rests on a surface showing flutes4 characteristic of glacial erosion5, we presume that it is glacial till. We propose here that deformation within the till is the primary mechanism by which the ice stream moves, and we discuss implications of this hypothesis.

Original languageEnglish (US)
Pages (from-to)57-59
Number of pages3
JournalNature
Volume322
Issue number6074
DOIs
StatePublished - Dec 1 1986

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ice stream
ice sheet
overburden
drain
boundary condition
radar
Antarctica
coast
sediment
water

All Science Journal Classification (ASJC) codes

  • General

Cite this

Alley, R. B., Blankenship, D. D., Bentley, C. R., & Rooney, S. T. (1986). Deformation of till beneath ice stream B, West Antarctica. Nature, 322(6074), 57-59. https://doi.org/10.1038/322057a0
Alley, Richard B. ; Blankenship, D. D. ; Bentley, C. R. ; Rooney, S. T. / Deformation of till beneath ice stream B, West Antarctica. In: Nature. 1986 ; Vol. 322, No. 6074. pp. 57-59.
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Alley, RB, Blankenship, DD, Bentley, CR & Rooney, ST 1986, 'Deformation of till beneath ice stream B, West Antarctica', Nature, vol. 322, no. 6074, pp. 57-59. https://doi.org/10.1038/322057a0

Deformation of till beneath ice stream B, West Antarctica. / Alley, Richard B.; Blankenship, D. D.; Bentley, C. R.; Rooney, S. T.

In: Nature, Vol. 322, No. 6074, 01.12.1986, p. 57-59.

Research output: Contribution to journalArticle

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AB - The behaviour and possible instability of the West Antarctic ice sheet depend fundamentally on the dynamics of the large ice streams which drain it. Model calculations show that most ice-stream velocity arises at the bed 1,2, and radar sounding has shown the bed to be wet3, but the basal boundary condition is not well understood. Seismic evidence from the Upstream B camp (UpB) on the Siple Coast of West Antarctica4 shows that the ice stream there rests on a layer of unconsolidated sediment averaging 5 or 6 m thick, in which the water pressure is only ∼50 kPa less than the overburden pressure. Because this thin layer occurs well inland beneath an active ice sheet and rests on a surface showing flutes4 characteristic of glacial erosion5, we presume that it is glacial till. We propose here that deformation within the till is the primary mechanism by which the ice stream moves, and we discuss implications of this hypothesis.

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Alley RB, Blankenship DD, Bentley CR, Rooney ST. Deformation of till beneath ice stream B, West Antarctica. Nature. 1986 Dec 1;322(6074):57-59. https://doi.org/10.1038/322057a0