Autonomous underwater vehicles (AUVs) and investigations of the ice-ocean interface in Antarctic and Arctic waters

• Published in: Journal of Glaciology
• Main Authors: Dowdeswell, JA, Evans, J, Mugford, R, Griffiths, G, McPhail, S, Millard, N, Stevenson, P, Brandon, MA, Banks, C, Heywood, KJ, Price, MR, Dodd, PA, Jenkins, A, Nicholls, KW, Hayes, D, Abrahamsen, EP, Tyler, P, Bett, B, Jones, D, Wadhams, P, Wilkinson, JP, Stansfield, K, Ackley, S
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2008
• Subjects: Antarctic; Arctic; Antarc*; Ice Shelf; Ice Shelves; Journal of Glaciology; Sea ice; Tidewater
• Online Access: https://ueaeprints.uea.ac.uk/id/eprint/24661/; https://doi.org/10.3189/002214308786570773

Limitations of access have long restricted exploration and investigation of the cavities beneath ice shelves to a small number of drillholes. Studies of sea-ice underwater morphology are limited largely to scientific utilization of submarines. Remotely operated vehicles, tethered to a mother ship by umbilical cable, have been deployed to investigate tidewater-glacier and ice-shelf margins, but their range is often restricted. The development of free-flying autonomous underwater vehicles (AUVs) with ranges of tens to hundreds of kilometres enables extensive missions to take place beneath sea ice and floating ice shelves. Autosub2 is a 3600kg, 6.7m long AUV, with a 1600m operating depth and range of 400km, based on the earlier Autosub1 which had a 500m depth limit. A single direct-drive d.c. motor and five-bladed propeller produce speeds of 1-2 ms-1. Rear-mounted rudder and stern-plane control yaw, pitch and depth. The vehicle has three sections. The front and rear sections are free-flooding, built around aluminium extrusion space-frames covered with glass-fibre reinforced plastic panels. The central section has a set of carbon-fibre reinforced plastic pressure vessels. Four tubes contain batteries powering the vehicle. The other three house vehicle-control systems and sensors. The rear section houses subsystems for navigation, control actuation and propulsion and scientific sensors (e.g. digital camera, upward-looking 300kHz acoustic Doppler current profiler, 200kHz multibeam receiver). The front section contains forward-looking collision sensor, emergency abort, the homing systems, Argos satellite data and location transmitters and flashing lights for relocation as well as science sensors (e.g. twin conductivity-temperature-depth instruments, multibeam transmitter, sub-bottom profiler, AquaLab water sampler). Payload restrictions mean that a subset of scientific instruments is actually in place on any given dive. The scientific instruments carried on Autosub are described and examples of observational data ...