Life in Extreme EnvironmentLife in deep freeze:

Lake Vostok, Antarctica

Readings: Nature, 415, 828-830

Science, 286, 2138-2141

Science, 286, 2141-2144

Science, 286, 2144-2147

Hidden depths: lake Vostok in Antarctica

Surface of Lake Vostok

Field camp of United States Antarctic Program at Vostok

Geophysical Measurements of Lake Vostok

Satellite images of several large lakes at the same scale

Drilling rig

The borehole beneath Vostok station extends into areas of frozen lake water

Time table

• 1989: drilling started at Russian Antarctic research station of Vostok to obtain information on past climate history

• 1990’s: evidence accumulated that there was a lake beneath the station

• 1995: a meeting in UK, decided to stop the drilling before the drilling bits touched the liquid water to contaminate it.

• 1998: Drilling halted with the borehole some 120 meters from the lake’s surface

Time table

• 1999: Ice cores from 3539-3750 m below analyzed for geochemistry and microbiology

• Nov, 2001: The group met in Itlay, and outlined a plan to access lake Vostok in 3-6 years.

• Meeting in Shanghai, China, July of 2002, and revised plan will be released. 10 countries will participate

Lake Vostok

• 240 km x 50 km• 1200 meters deep of liquid water• Lake bottom covered by sediment of hundreds of

meters thick• Temperature is –3oC, but unfrozen• Totally dark• Low nutrient levels• 380 atmosphere pressure• Complete isolation for millions of years

Map and Geochemical Characteristics

1999 discoveries

• Gas content

• Electrical conductivity measurement

• Crystal size

• # of inclusions

• Isotopic evidence

Isotopic evidence for frozen lake water

Sketch of Vostok core site

SEM and AFM micrographs of microbes from ice core

Epifluorescence and SEM micrographs of microbes from ice cores

Evidence for microbes in ice cores

• Epifluorescence and SEM evidence– Hundreds to thousands of cells per ml

• Molecular work – Alpha and beta proteobacteria

• Heterotrophy• Incorporation of radiolabeled compounds• LPS concentration• Not culutrable

Incorporation of radiolabels

Energy source

• Glacier ice from above

• Geothermal energy– Intracontinental rife zone similar to East Africa

Implication

• Life in Europa – moon of Jupiter

Further information

• http://science.nasa.gov/newhome/headlines/ast10dec99_2.htm

• http://www.ldeo.columbia.edu/~mstuding/vostok.html

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