Can an ice shelf break up in the middle of winter?
In winter glaciers like this one are usually protected by pack ice even in summer in a small boat it is quite often very calm inside the pack ice, it acts as a sort of break water. The image here appears to show mostly clear water either side of Wilkins so a big winter storm would act directly on the glacier, wave action and storm surge are the main damaging forces. Large ice sheets have quite a bit of flex and can deal with tides and normal wave movement. Winter sea ice surrounds Antarctica (including the Peninsula) the link below shows last years sea ice extent, but sea ice can also be affected by weather and areas can be pushed out to sea and broken up even in winter and while sea ice is amazingly strong, you can drive a 10 ton bulldozer on sea ice only a few of feet thick, a storm can brake up 100s of square km in a few hours. The second link gives some idea of the forces and cause of these storms.
