In the early hours of 25th December 2012, an attempt to explore Subglacial Lake Ellsworth
deep beneath the West Antarctic ice sheet was called off. This UK project, involving
the British Antarctic Survey, the National Oceanography Centre and several Universities,
had been in planning for over 10 years. The ambition was to access the lake using
a specially-engineered hot-water drill through 3 km of ice and, using the hole created
deploy probes to take samples and measurements to look for life in the lake and acquire
records of past ice and climate change.
Drilling was ceased after the main borehole failed to link with a subsurface cavity
of water, built up over ~40 hours. Without this link, insufficient water was available
to continue drilling downwards to the lake.
On return to the UK, an external review of the programme was undertaken by the Natural
Environment Research Council (NERC) to formally assess the reasons for the fieldwork
failure, and to make recommendations on the modifications necessary for success.
From this review, completed in June 2013, a pathway was formulated along which a
second attempt to explore the lake can be developed.
The original project designed a full blueprint for subglacial lakes research, involving
access to the subglacial environment through deep-drilling, direct measurement and
sampling of water and sediment by the construction of a probe and sediment corer,
and environmental protocols to ensure cleanliness. Changes to this blueprint are
now being planned.
Hot-water drilling is still regarded as the only feasible scheme by which clean and
efficient access to the deep subglacial environment can be assured. The lessons learned
from the Lake Ellsworth experience are substantial, however, and demonstrate that
considerable technological and methodological advances are necessary for successful
future research on subglacial lakes beneath thick (>2 km) ice. The changes needed
are feasible, however, and we remain confident that the field programme can be restarted
once they are complete.
The scientific goals that drive subglacial lakes research, concerning life in extreme
environments and past climate change, remain significant and are still to be achieved.
Of the ~400 known Antarctic subglacial lakes, Lake Ellsworth endures as an excellent
candidate for exploration. Given the work needed to minimise the risk of repeat failure,
a return mission to this lake may take several years.
Looking ahead, if the sub-ice continent of Antarctica is to be explored and understood,
it is essential that a clean, rapid, efficient means by which it can be accessed
be developed. As a consequence the long-term legacy of the Lake Ellsworth programme
may yet be truly significant.
Martin Siegert will present public lectures on the ‘Lake Ellsworth programme – 1
year on’ to the Cambridge University Scientific Society (20:00-21:15 in Cambridge
University’s Department of Pharmacology Lecture Theatre) on 3rd December (http://www.scisoc.com/subglacial-lake-ellsworth-prof-martin-siegert/),
and to the Geological Society as part of the Shell London Lecture Series, Burlington
House, London (3pm and 6pm) 18th December (www.geolsoc.org.uk/beneathice).
The latter presentation will be shown live online as a webcast.
Both events require tickets: please see the websites above for information on how
to obtain them.
For further information, please contact Martin Siegert: firstname.lastname@example.org