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Project Progress

Subglacial lakes are the focus of studies of life in extreme environments because they may resemble habitats on Mars and icy satellites in the outer solar system. ISBOX II succeeded in drilling through 300 meters of glacial ice to sample a subglacial lake beneath the Vatnajökull glacier in Iceland, in June 2006. This is only the second such lake to be directly sampled (the first was a nearby lake in the Grímsvötn volcanic caldera in 2002 by members of the same team). The expedition was partly funded by UH-NAI and by several Icelandic science and government institutes. The drilling used a new hot water drill designed and constructed by the Icelandic team. This drill used filtration, ultraviolet radiation, and heating of the water to 99 C to sterilize the drilling water so as to minimize contamination of the lake. Confirmation of access to the lake was achieved by observing the adjustment of the water level in the borehole as hydrostatic equilibrium was achieved with the floating overlying lake and the change in tension on the hose to the drill head. A temperature profile of the lake was measured and the depth recorded using a separate line. The lake is 100 meters deep (below the ice-water interface) at the drilling site and the temperature is about 4 C throughout most of the water column. A gas-tight water sample was retrieved from within about 2 meters of the bottom of the lake using a dedicated sampler designed and built at UH. Verification of sampling was done by adding a dye to the borehole water, and checking that the lake sample was colorless. Degassing of the sample was observing upon retrieval of the sample from the sampler (done through a gas-tight system). Strong sulfide odor as well as detection of sulfide in the water and non-detection of oxygen confirms the sample was anoxic. Samples are being analyzed for geochemistry and biology and results will be discussed at an upcoming conference. A pressure and temperature sensor was left in the lake and data will be downloaded at regular intervals to search for changes through the next jökulhlaups (episodic drainage) cycle.

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