A huge iceberg, roughly the size of the county of Norfolk in the United Kingdom or the state of Delaware in the United States, looks set to break away from the Larsen C ice shelf on the Antarctic Peninsula. Larsen C is more than twice the size of Wales. Satellite observations from December 2016 show a growing crack in the ice shelf which suggests that an iceberg with an area of up to 5,000 square kilometers is likely to calve soon.
British Antarctic Survey researchers have a long running research programme to monitor ice shelves from both above and below to understand the causes and implications of the rapid changes observed in the region.
During the current Antarctic field season, a glaciology research team has been on Larsen C using seismic techniques to survey the seafloor beneath the ice shelf. As a break up looks likely the team has not set up camp on the ice as usual. Instead they have made field trips by twin otter aircraft supported from Rothera Research Station.
Ice shelves in normal situations produce an iceberg every few decades. There is not enough information to know whether the expected calving event on Larsen C is an effect of climate change or not, although there is good scientific evidence that climate change has caused thinning of the ice shelf. Once the iceberg has calved the big question is whether the entire ice sheet may collapse. This is something that British Antarctic Survey teams have been monitoring and why glaciologists were deployed to work on Larsen C in the past few weeks.