Document DetailsTechnical innovations and optimizations for intermediate ice-core drilling operations
|Authors:||Triest J, Mulvaney R, Alemany O|
|Periodical/Journal:||Annals of Glaciology|
The British Antarctic Survey, in collaboration with Laboratoire de Glaciologie et Geeophysique de l'Environnement, has in recent years successfully drilled to bedrock on three remote sites around the Antarctic Peninsula. Based on the experience from the multi-season project at Berkner Island (948 m depth, 2002-05) we optimized the drill set-up to better suit two subsequent single-season projects at James Ross Island (363 m depth, 2008) and Fletcher Promontory (654 m depth, 2012). The adaptations, as well as the reasons for them, are discussed in detail and include a drill tent set-up without a trench; drilling without a borehole casing with a relatively low fluid column height; and using a shorter drill. These optimizations were aimed at reducing cargo loads and installation time while maintaining good core quality, productivity and a safe working environment. In addition, we introduce a number of innovations, ranging from a new lightweight cable tensioning device and drill-head design to core storage and protection trays. To minimize the environmental impact, all the drill fluid was successfully recovered at both sites and we describe and evaluate this operation.