A proposed sterile sampling system for Antarctic subglacial lakes

In recent years, many subglacial lakes beneath the Antarctic Icecap have been discovered (M. J. Siegert et al., Antarct. Sci., 8,281,1996). It is presumed that these lakes have been isolated from the greater terrestrial and marine environment for a long period of time (P. Barrett, SCAR International Workshop on Subglacial Lake Exploration, Vol. 2,17,1999). As a result, there is considerable interest in the geochemical and biological makeup of these lakes. International efforts are ongoing to determine the best methodology to study and/or sample the ice, water, and sediments associated with these lakes. The authors propose a sterile drill to penetrate and sample subglacial lakes without contamination. The system uses a hot-water access drill to reach the vicinity of the lake, followed by insertion of an electrically-heated completion drill and sample retrieval system. The operation of the system is such that no open conduit exists between the lake and the surface at any time, thereby preserving the isolation, and hopefully the integrity, of the lake. An appendix describes an alternative sampling technology.