We investigate the elevation and mass-balance response of tributary glaciers following the
loss of the Larsen A and B ice shelves, Antarctic Peninsula (in 1995 and 2002 respectively). Our study
uses MODIS imagery to track ice extent, and ASTER and SPOT5 digital elevation models (DEMs) plus
ATM and ICESat laser altimetry to track elevation changes, spanning the period 2001–09. The measured
Larsen B tributary glaciers (Hektoria, Green, Evans, Punchbowl, Jorum and Crane) lost up to 160 m in
elevation during 2001–06, and thinning continued into 2009. Elevation changes were small for the more
southerly Flask and Leppard Glaciers, which are still constrained by a Larsen B ice shelf remnant. In the
northern embayment, continued thinning of >3 m/yr on Drygalski Glacier, 14 years after the Larsen A
ice shelf disintegrated, suggests that mass losses for the exposed Larsen B tributaries will continue for
years into the future. Grounded ice volume losses exceed 13 km3 for Crane Glacier and 30 km3 for
the Hektoria–Green–Evans glaciers. The combined mean loss rate for 2001–06 is at least 11.2 Gt/yr. Our
values differ significantly from published mass-budget-based estimates for these embayments, but are a
reasonable fraction of GRACE-derived rates for the region (~40 Gt/yr).
Location map (background Modis Mosaic of Antarctica, Scambos et al., 2007). Click on the image for higher resolution.
Image showing the dramatic ice surface lowering during 2001-06 after the collapse of the Larsen B Ice Shelf (click on the image for higher resolution).