Steep reverse bed slope at the grounding line of the Weddell Sea sector in West Antarctica

Neil Ross, Robert George Bingham, Hugh F.J. Corr, Fausto Ferraccioli, Tom A. Jordan, Anne Le Brocq, David M. Rippin, Duncan Young, Donald D. Blankenship, Martin J. Siegert

Research output: Contribution to journalArticle

73 Citations (Scopus)

Abstract

The West Antarctic Ice Sheet lies on a bed that is, in places, >1.5 km below sea level. A positive ice-loss feedback is theorised to occur by grounding line retreat across a deepening bed, which accelerates ice floatation and ice-sheet decay. This process could raise global sea level by >3 m. Attention has been given to ice-sheet change in the Siple Coast and Amundsen Sea embayment sectors of West Antarctica. Here, we present radio-echo sounding information from the ice-sheet’s third sector, the Weddell Sea embayment, revealing a major subglacial basin immediately upstream of the grounding line. The reverse bed slope is steep (~400 m over ~40 km) and contains little small-scale topography that would delay retreat, unlike the more complex reverse slopes in the Amundsen Sea embayment. The basin floor is smooth and flat, similar to the Siple Coast, suggesting it has been covered with marine sediment and, therefore, was previously deglaciated. Upstream of the basin well-defined glacially carved fjords, with bars at their mouths, testify to the position of a former ice margin ~200 km inland from present. As the ice sheet is close to floatation over the basin, the region is at a physical threshold of substantial change.
Original languageEnglish
Pages (from-to)393-396
Number of pages4
JournalNature Geoscience
Volume5
Issue number6
Early online date9 May 2012
DOIs
Publication statusPublished - Jun 2012

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grounding line
ice sheet
basin
sea level
ice
echo sounding
ice margin
coast
fjord
marine sediment
Antarctica
sea
topography
radio

Keywords

  • climate science
  • cryospheric science
  • paleoclimate and palaeoceanography
  • structural geology, tectonics and geodynamics

Cite this

Ross, N., Bingham, R. G., Corr, H. F. J., Ferraccioli, F., Jordan, T. A., Le Brocq, A., ... Siegert, M. J. (2012). Steep reverse bed slope at the grounding line of the Weddell Sea sector in West Antarctica. Nature Geoscience, 5(6), 393-396. https://doi.org/10.1038/ngeo1468

Steep reverse bed slope at the grounding line of the Weddell Sea sector in West Antarctica. / Ross, Neil; Bingham, Robert George; Corr, Hugh F.J.; Ferraccioli, Fausto; Jordan, Tom A.; Le Brocq, Anne ; Rippin, David M.; Young, Duncan; Blankenship, Donald D.; Siegert, Martin J.

In: Nature Geoscience, Vol. 5, No. 6, 06.2012, p. 393-396.

Research output: Contribution to journalArticle

Ross, N, Bingham, RG, Corr, HFJ, Ferraccioli, F, Jordan, TA, Le Brocq, A, Rippin, DM, Young, D, Blankenship, DD & Siegert, MJ 2012, 'Steep reverse bed slope at the grounding line of the Weddell Sea sector in West Antarctica', Nature Geoscience, vol. 5, no. 6, pp. 393-396. https://doi.org/10.1038/ngeo1468
Ross N, Bingham RG, Corr HFJ, Ferraccioli F, Jordan TA, Le Brocq A et al. Steep reverse bed slope at the grounding line of the Weddell Sea sector in West Antarctica. Nature Geoscience. 2012 Jun;5(6):393-396. https://doi.org/10.1038/ngeo1468
Ross, Neil ; Bingham, Robert George ; Corr, Hugh F.J. ; Ferraccioli, Fausto ; Jordan, Tom A. ; Le Brocq, Anne ; Rippin, David M. ; Young, Duncan ; Blankenship, Donald D. ; Siegert, Martin J. / Steep reverse bed slope at the grounding line of the Weddell Sea sector in West Antarctica. In: Nature Geoscience. 2012 ; Vol. 5, No. 6. pp. 393-396.
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