Nov 28, 2016

Accelerated ice shelf rifting and retreat at Pine Island Glacier, West Antarctica

by
Jeong, Seongsu, Howat, Ian M., Bassis, Jeremy N.
,
Geophysical Research Letters
  • States that Pine Island Glacier has undergone several major iceberg calving events over the past decades
  • States that these typically occurred when a rift at the heavily fractured shear margin propagated across the width of the ice shelf
  • States that this type of calving is common on polar ice shelves, with no clear connection to ocean-ice dynamic forcing
  • Reports, in contrast, on the recent development of multiple rifts initiating from basal crevasses in the center of the ice shelf, resulted in calving further upglacier than previously observed
  • Observes that coincident with rift formation was the sudden disintegration of the ice mélange that filled the northern shear margin, resulting in ice sheet detachment from this margin
  • Examines ice velocity, which suggests that this internal rifting resulted from the combination of a change in ice shelf stress regime caused by disintegration of the mélange and intensified melting within basal crevasses, both of which may be linked to ocean forcing