Lake Ellsworth (Antarctica)
|Surface area||30 km2 (12 sq mi)|
|Max. depth||150 m (490 ft)|
|Surface elevation||1,400 m (4,600 ft) below sea level|
Lake Ellsworth is a subglacial lake located in West Antarctica under approximately 3.4 km (2.1 mi) of ice. It is approximately 10 km long and is estimated to be 150 m (490 ft) in depth. The lake is named after the American explorer Lincoln Ellsworth.
Lake Ellsworth was discovered in 1996 by British scientist Professor Martin Siegert; it is one of 387 known subglacial Antarctic lakes and it is a target site for exploration due to the speculation that new forms of microbial life could have evolved in the unique habitats of Antarctica’s sub-glacial lakes after half a million years of isolation. Life in subglacial lakes must adapt to total darkness, low nutrient levels, high water pressure and isolation from the atmosphere. Subglacial lakes thus represent unique biological habitats. The lake remains liquid deep below the Antarctic surface because the pressure exerted by thousands of meters of ice drives down the freezing point of water.
On 2 March 2009 the UK's Natural Environment Research Council authorized a team of British scientists to drill through the overlaying ice to the surface of the lake in December 2012. The drilling was to be overseen by The Scientific Committee on Antarctic Research from the International Council for Science. The British team spent sixteen years developing the technology to explore the lake using methods that would not lead to chemical or biological contamination. Scientists hoped to use a hot water jet to drill a borehole 36 centimeters (14 inches) wide down through the ice to the lake, to enable a probe to retrieve sediment and water to be analyzed for microorganisms. This would be a test to determine if water correlates with life under extreme pressure, cold and nutrient deficiencies. If the group did not identify life, it would provide a limit where there is water and no life.
Radar surveys indicated that the lake floor sediments are suitable for coring, which could contain a record of ice sheet history. Scientists think that the sediment and water samples could also hold key information about climate change. In January 2012 the drilling was scheduled to start between November 2012 and January 2013. Depending on the weather, the team expected to drill continuously for 100 hours to reach the lake. 
On 12 December 2012 the British research team of twelve scientists and engineers began to bore the ice-sheet to obtain water samples. Using a high-pressure hose and sterilised water at near-boiling point, they hoped to bore a passage through more than two miles of ice. The drilling process was expected to last five days and would be followed by a rapid sampling operation. Professor Siegert said that the search for life in such an extreme environment could open up possibilities for life on other worlds such as Jupiter's moon Europa. On 25 December 2012 it was announced that the project had been called off, after attempts to link two 300m-deep boreholes failed.
- "The Exploration of Subglacial Lake Ellsworth". The University of Edinburgh. Retrieved 2012-09-07.
- Siegert, Martin J. (2004). "Subglacial Lake Ellsworth: A candidate for in situ exploration in West Antarctica". Geophysical Research Letters 31 (23): L23403. Bibcode:2004GeoRL..3123403S. doi:10.1029/2004GL021477.
- Evidence of Lake Ellsworth (1996)
- Siegert, Martin J. and the Lake Ellsworth Consortium, "Exploration of Subglacial Lake Ellsworth", Poster, University of Bristol, September 2004
- Antarctica Researchers Seek Life in Lake 2 Miles Under Ice. By Alex Morales. September 7, 2012
- SALE plan for subglacial lake exploration
- Search for Life in Antarctica's Ice-Covered Lake Takes Off. By Trevor Stokes, September 7, 2012
- "Final frontier: mission to explore buried ancient Antarctic lake given green light". Natural Environment Research Council (NERC). 2009-03-02. Retrieved 2011-10-11.
- "BBC News - Scientists search for life under Antarctic icecap". Bbc.co.uk. Retrieved 2011-10-11.
- Mustain, Andrea (Jan 16, 2012). "British Antarctic Survey Scientists Seek To Drill To Lake Ellsworth". Huffington Post. Retrieved 01-17-2012.
- "Drilling begins at lake hidden beneath Antarctic" by David Shukman at bbc.co.uk
- "Press Release - Antarctic lake mission called off". British Antarctic Survey. Dec 27, 2012. Retrieved 12-27-2012.
- The Exploration of Subglacial Lake Ellsworth - The University of Edinburgh.
- PDF (340 KiB)
- Woodward, J., A. M. Smith, N. Ross, M. Thoma, H. F. J. Corr, E. C. King, M. A. King, K. Grosfeld, M. Tranter, and M. J. Siegert (2010), Location for direct access to subglacial Lake Ellsworth: An assessment of geophysical data and modeling, Geophysical Research Letters, 37, L11501, doi:10.1029/2010GL042884