Disintegration and Buttressing Effect of the Landfast Sea Ice in the
Larsen B Embayment, Antarctic Peninsula
Abstract
The speed-up of glaciers following ice shelf collapse can accelerate ice
mass loss dramatically. Investigating the deformation of landfast sea
ice enables studying its resistive (buttressing) stresses and mechanisms
driving ice collapse. Here, we apply offset tracking to Sentinel-1 A/B
synthetic aperture radar (SAR) data to obtain a 2014-2022 time-series of
horizontal velocity and strain rate fields of landfast ice filling the
embayment formerly covered by the Larsen B Ice Shelf, Antarctic
Peninsula until 2002. The landfast ice disintegrated in 2022, and we
find that it was precipitated by a few large opening rifts. Upstream
glaciers did not accelerate after the collapse, which implies little
buttressing effect from landfast ice, a conclusion supported by the
near-zero correlation between glacier velocity and landfast ice area.
Our observations suggest that buttressing stresses are unlikely to be
recovered by landfast sea ice over sub-decadal timescales following the
collapse of an ice shelf.