Document DetailsThe BAS ice-shelf hot-water drill: design, methods and tools
|Authors:||Makinson K, Anker PGD|
|Keywords:||glaciological instruments and methods, ice shelves|
|Periodical/Journal:||Annals of Glaciology|
The 2011/12 Antarctic field season saw the first use of a new British Antarctic Survey (BAS) ice-shelf hot-water drill system on the Larsen C and George VI ice shelves. Delivering 90 L/min at 80°C, a total of five holes >30 cm in diameter at three locations were successfully drilled through almost 400 m of ice to provide access to the underlying ocean, including the first access beneath the Larsen C ice shelf. These access holes enabled the deployment of instruments to measure sea-water conductivity, temperature, depth and microstructure, the collection of water samples and up to 2.9 m long sediment cores, before long-term oceanographic moorings were deployed. The simple modular design allowed for Twin Otter aircraft deployment, rapid assembly and commissioning of the system, which proved highly reliable with minimal supervision. A number of novel solutions to various operational sub-ice-shelf profiling and mooring deployment issues were successfully employed through the hot-water drilled access holes to aid the positioning, recovery and deployment of instruments. With future activities now focusing on the Filchner-Ronne Ice Shelf, the drill has been upgraded from its current 500m capability to 1000m with additional drill hose and further generator, pumping and heating modules.