We can report a further extension of the rift which threatens to calve an iceberg measuring more than 5,000 sq. km in area from the Larsen C Ice Shelf. Imagery acquired on 19th January by ESA’s Sentinel-1 satellites shows a further 10 km of rift growth since January 1st, bringing its total length to 175 km. The rift has continued to grow parallel to the shelf edge, so the iceberg remains attached by around 20 km of ice.

The current location of the rift on Larsen C, as of January 19 2017. Labels highlight significant jumps. Tip positions are derived from Landsat (USGS) and Sentinel-1 InSAR (ESA) data. Background image blends BEDMAP2 Elevation (BAS) with MODIS MOA2009 Image mosaic (NSIDC). Other data from SCAR ADD and OSM.

When it calves, the Larsen C Ice Shelf will lose more than 10% of its area to leave the ice front at its most retreated position ever recorded; this event will fundamentally change the landscape of the Antarctic Peninsula. We have previously shown that the new configuration will be less stable than it was prior to the rift, and that Larsen C may eventually follow the example of its neighbour Larsen B, which disintegrated in 2002 following a similar rift-induced calving event.

The MIDAS Project will continue to monitor the development of the rift and assess its ongoing impact on the ice shelf. Further updates will be available on this blog, and on our Twitter feed.

The development of the rift length and width, up to January 19 2017
An animation of the opening of the rift, as observed by ESA's Sentinel-1 satellites