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SUMMARY:Antarctic ice flow: what can we learn by combining models and meas
 urements? - Robert Arthern\, British Antarctic Survey
DTSTART:20141030T130000Z
DTEND:20141030T133000Z
UID:TALK54998@talks.cam.ac.uk
CONTACT:Dr Dan Jones
DESCRIPTION:Nowadays there are a large number of satellite and airborne ob
 servations of the large ice sheet that covers Antarctica. These include ma
 ps of the surface elevation\, the ice thickness\, the snowfall rate\, the 
 surface flow speed of glaciers\, and maps of how the surface elevation is 
 changing over time. Uncertainty in the possible rate of future sea level r
 ise motivates using all of these observations and computational models of 
 the flowing ice to make projections of how the ice sheet as a whole might 
 behave in future\, but this is still a challenge. The ice sheet can be sev
 eral kilometres thick\, but most of the observations identify quantities a
 t the upper surface of the ice sheet\, not within its bulk.  To make usefu
 l predictions using glaciological models of the ice sheet we need accurate
  information from beneath the surface.  We need to find out where cold-bas
 ed parts of the ice sheets are frozen immobile onto rock\, and where the i
 ce rests on slippery water-lubricated sediment that allows it to flow rapi
 dly towards the ocean. We also need to assess which parts of floating ice 
 shelves around the edge of Antarctica are damaged and unable to provide mu
 ch resistance to the ice that flows from the main part of the ice sheet in
 to the ocean. We need information about how quickly the ice is flowing dee
 p within the ice sheet\, and which physical processes beneath the ice can 
 affect this flow. Finally\, we need to understand how the future behaviour
  of the ice sheet relates to what we observe today and how changes happeni
 ng now at the edge of the ice sheet could in due course affect ice that is
  presently hundreds of kilometres inland. This talk describes how a combin
 ation of ice sheet modelling and measurements from satellites and aircraft
  has allowed us to explore these questions and visualise what is happening
  in parts of Antarctica that we cannot visit.
LOCATION:British Antarctic Survey\, conference room
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