Brunt Ice Shelf [Candidate]
Basic CryoNet Cluster Information

This research project uses a range of different technologies to monitor glaciological change on the Brunt Ice Shelf – the location of Halley VI Research Station. In 2012 satellite monitoring of this ice shelf revealed the first signs of movement in a chasm that had lain dormant for at least 35 years. Glaciologists classify very large cracks in the ice shelf which clearly go all the way through to the sea as “chasms”, and narrow cracks that go an indeterminate depth as crevasses or cracks.

In 2015/16 field season glaciologists used ice penetrating radar technologies to ‘ground truth’ satellite images to calculate the most likely path and speed of chasms and cracks in the ice. In October 2016 a crack emerged some 17km to the north of the research station across the route sometimes used to resupply Halley.

The Brunt Ice Shelf is the floating extension of the grounded ice sheet. It is composed of freshwater ice that originally fell as snow, either in situ or inland and brought to the ice shelf by glaciers. Cracks appear continuously on ice shelves as the ice deforms. Frequently, cracks that form during the summer months heal again over winter. At Halley a long-term ice-monitoring project, that uses satellite and radar data, detected new growth in a chasm that has been dormant for around 30 years.

Observations reveal that a particular feature – Chasm A – has been growing continuously since 2012. Observations revealed that the crack tip is moving gradually upstream of the research station. The research station has been relocated to avoid this chasm.

http://nora.nerc.ac.uk/514896/1/Gudmundsson.pdf