Ice Shelves
Photo: Ice shelf
Floating ice shelves and glacier tongues, which fringe 44% of the Antarctic coastline, are that part of the ice sheet system most vulnerable to climate change. They are in direct contact with the ocean, and sub-glacial ocean circulation directly couples them to the global climate system. Most of the Antarctic continental ice is discharged through ice shelves and glacier tongues and changes to the floating ice has the potential to change the flow in ice streams and outlet glaciers that drain mass from the interior of the ice sheet.
The rapid disintegration of several Antarctic ice shelves over recent decades has been attributed to combinations of atmospheric and oceanic influences, internal ice shelf dynamics and fracture and rift development. Uncertainty about how these changes at the ice margin affect the interior flow leads to significant uncertainty about future contributions of Antarctica to global sea-level.
Image (courtesy ESA): Cryosat-2 in Space
ACE is developing improved models of sub-shelf ocean circulation, ice shelf-ocean interaction and the influence of changing ice shelves on grounding lines and ice stream dynamics. This effort is focussed on the Amery Ice Shelf (70oS, 70oE) where there is a long record of Australian field measurements, excellent coverage by remote sensing satellites, and a unique multi-year record of changes and variability in the ocean cavity beneath the ice shelf from previous ACE programs of ice shelf drilling and deployment of ocean moorings.
Projects and project leaders
Ice-ocean interaction beneath ice shelves and its impacts: Dr John Hunter, Dr Roland Warner