Featured Science Paper
Marine ice in Larsen Ice Shelf
This paper describes interaction between Larsen ice shelves and the ocean beneath. These ice shelves are important indicators of climate change; a large section of Larsen B disintegrated in February 2002 and the next ice shelf in line, Larsen C, may already be thinning.
The study revisited some old radar data from a BAS airborne campaign in 1997–98, finding intriguing gaps in the data that follow ice flow bands. Gaps like these can indicate that the ice shelf is made up of ‘marine’ ice, formed from frozen seawater instead of compacted snow. These marine ice bands visibly stabilise Larsen B and C ice shelves, stopping the penetration of rifts and controlling iceberg calving.
A possible formation mechanism for this marine ice is tested in the study using a simple model of the ocean beneath Larsen B and C. Using 2002 BAS ocean data to force the model, oceanic freezing occurs beneath all of the observed marine ice bands. If the modelled ocean is warmed up, freezing stops. As a result, it is possible that any warming of the ocean beneath Larsen C Ice Shelf could remove the stabilising influence of its marine ice.
Holland, P.R., Corr, H.F.J., Vaughan, D.G., Jenkins, A., Skvarca, P. 2009
Geophysical Research Letters, 36, No.11, L11604, doi:10.1029/GL038162, 6p.