Rift in Antarctic Glacier: A Unique Chance to Study Ice Shelf Retreat

It happened again, but this time it was caught in the act. During the last week of September 2011 a large transverse rift developed across the floating terminus of West Antarctica's Pine Island Glacier, less than 5 years after its last large calving event, in 2007 (Figure 1). Pine Island Glacier's retreat has accelerated substantially in the past 2 decades, and it is now losing 50 gigatons of ice per year, or roughly 25% of Antarctica's total annual contribution to sea level rise [ Rignot et al. , 2008]. The glacier's recent accelerated retreat is likely triggered by ocean warming and increased submarine melting. As such, it is of significant interest to glaciologists and of heightened societal relevance.