Antarctic ice rift close to calving, after growing 17km in 6 days.

British Antarctic Survey (BAS) recently captured this video footage of a huge crack in the Larsen C Ice Shelf, on the Antarctic Peninsula.

Currently a huge iceberg, roughly the size of Norfolk, looks set to break off Larsen C Ice Shelf, which is more than twice the size of Wales. Satellite observations from February 2017 show a growing crack in the ice shelf which suggests that an iceberg with an area of more than 5,000 km² is likely to calve soon.

Researchers from the UK-based MIDAS project, led by Swansea University, have reported several rapid elongations of the crack in recent years. BAS scientists are involved in a long-running research programme to monitor ice shelves to understand the causes and implications of the rapid changes observed in the region.

They shot this footage as they flew over the ice shelf on their way to collect science equipment. 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. Because a break up looks likely the team did not set up camp on the ice as usual.

Instead they made one-off trips by twin otter aircraft supported from the UK’s 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 Larsen C will start to retreat.

References

• Content: Antarctic ice rift close to calving, after growing 17km in 6 days http://www.swansea.ac.uk/media-centre/latest-research/antarcticiceriftclosetocalvingaftergrowing17kmin6days.php
• Larsen C video by British Antarctic Survey https://www.youtube.com/watch?v=WAM0tZB0aIc

Related

• Larsen Ice Shelf https://en.wikipedia.org/wiki/Larsen_Ice_Shelf
• Larsen Ice Shelf Meets Open Water (2010) https://www.nasa.gov/mission_pages/icebridge/multimedia/fall09/LarsenMeetsOpenWater.html
• Antarctica’s Larsen B Ice Shelf: The Final Act https://www.youtube.com/watch?v=H2a3Oemo1e4