ASPI: Antarctic Subglacial Processes and Interactions

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ASPI Antarctic Subglacial Processes and
Interactions

• Frank PATTYN1, Marc DE BATIST2, Hugo DECLEIR1,
  Reginald LORRAIN3, Roland SOUCHEZ3
• 1 Department of Geography, Vrije Universiteit
  Brussel, Brussels, Belgium
• 2 Renard Centre of Marine Geology, University of
  Ghent, Belgium
• 3 Laboratoire de Glaciologie, Universite Libre de
  Bruxelles, Brussels, Belgium

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Background 1

• AMICS Antarctic ice sheet dynamics and climate
  change modelling and ice composition studies
• AMICS research project of the Belgian Antarctic
  Research Programme of the Belgian Federal Science
  Policy Office (BELSPO)
• BELSPO coordinates all research activities with
  respect to the Antarctic
• New call of proposals for Belgian Antarctic
  Programme in May 2005 4 year projects, i.e.
  last year coincides with IPY

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Background 2

• BNCAR Belgian National Committee on Antarctic
  Research launched the call for Belgian
  researchers to participate in IPY
• Projects endorsed at international level (IPY)
  might be receiving extra funding from BELSPO
  during IPY
• Most research teams of the Antarctic Research
  programme sent in an IPY proposal (coordinated by
  BNCAR)

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ASPI Antarctic Subglacial Processes and
Interactions

• ASPI research proposal for next Belgian
  Antarctic Research Programme (2005-2009)
• ASPI IPY proposal at the end of the project
• ASPI not only about subglacial lakes, but also
  ice/bed interaction or ice/ocean interaction,
  e.g. grounding lines

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ASPI objectives

• To clarify the interactions between the ice sheet
  and the subglacial environment
• To elucidate the effect of these interactions on
  the transient behaviour of the Antarctic ice
  sheet with changing climate
• To understand the ice flow complexity involved so
  that paleo-records (ice cores, erosional imprints
  and sedimentary remnants on the Antarctic
  shelves) can be better understood and interpreted
  more accurately.

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ASPI outline

• Investigate subglacial processes and interactions
  with the ice sheet, through a multidisciplinary
  approach.
• numerical ice-sheet modelling
• ice-core analysis
• continental shelf investigations

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ASPI
Grounding line / zone transition zone between
high stress and low traction
Subglacial processes Basal water Till deformation
Ice stream
Grounding line - Transition zone
Ocean
Ice sheet
Ocean warming Grounding line retreat
Origin Mechanisms Interactions
Subglacial lake
IMPACT
Sea-level rise
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Grounding lines

• Marine ice sheet instability

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Ice sheet shear stress
THEORY
Ice stream grounding line mixture
Ice shelf normal stress
Ub0
0 lt Ub lt Us
Ub Us
High basal traction
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Low basal traction
ß2
Zero basal traction
0
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Dynamics

• Retreat advance
• Proglacial lake subglacial lake
• Stress transfer width of transition zone
• Influence on stress regime

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Possible grounding line research for IPY

• Investigate grounding line of a small ice shelf
  to understand processes and interactions
• Drill ice core at the grounding line (basal ice
  analysis)
• Radio echo sounding
• Operate ROV under the ice shelf and sample near
  grounding line
• Modelling

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Belgian Partners (1)

• Renard Centre of Marine Geology, University of
  Ghent
• Development of (seismic) methods and techniques
• Continental margin research
• Sub-ice shelf processes and grounding line
  sampling

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Belgian Partners (2)

• Laboratoire de Glaciologie, Université Libre de
  Bruxelles
• Study of frozen lakes of the Dry Valleys
• Interpretation of Vostok basal ice
• Interpretation of the basal part of EPICA DC,
  i.e. possible traces of ice passage over one of
  the subglacial lakes in the vicinity of the
  drilling site...
• Investigation of the basal part of the Berkner
  Island core (dirty ice / marine ice).

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Belgian Partners (3)

• Department of Geography, Vrije Universiteit
  Brussel
• Numerical modelling of the cryosphere
• Development and refinement of ice sheet and ice
  stream models
• Including subglacial processes at the ice / bed
  interface in numerical ice-sheet models
• Numerical analysis of transition zones (contact
  ice subglacial lakes ice ocean grounding
  lines)