Lake Vostok

1
Lake Vostok

• Holt Hancock
• GEOL 445
• 4/27/09

2
Introduction

• Research Methods
• Physical Environment
• Possibilities for Life
• Planetary Studies

http//svs.gsfc.nasa.gov/vis/a000000/a000900/a0009
96/
3
Introduction

• 4 km below East Antarctic Ice Sheet
• Largest (known) subglacial lake
• Lake Ontario (Siegert, 2000)
• Discovered 1996
• Kapitsa et al.
• Tectonic Setting (Studinger, 2003)
• Rift Valley
• Geothermal energy?
• Isolated from atmosphere 15 million yrs.
  (Siegert, 2005)

http//www.d.lane.btinternet.co.uk
4
Research Methods

• Radio-echo sounding
• Aerial Survey
• 1973 Oswald and Robin
• 1996 Kapitsa et al.

(Oswald and Robin, 1973)
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Research Methods

• Radio-echo sounding
• Aerial Survey
• 1973 Oswald and Robin
• 1996 Kapitsa et al.
• Ice Cores
• Vostok Station
• 420,000 year record (Christner et al. 2003)
• Meteoric/Accreted Ice

http//ec.europa.eu/research/rtdinfo/special_pol/0
3/images/10_dessinlac_2_fr_vec_3555_en.jpg
6
Physical Processes

• Ice flow generally SW over lake
• 4.2 m / y (Siegert et al., 2001)
• Ice-water interface
• Sloping Hydrostatic Equilibrium
• Melting (PMP)/Accretion
• Islands, Sediments?

(Siegert et al., 2003)
7
Physical Processes

• Circulation
• Modeling (Mayer et al. 2003 Thoma et al. 2008)
• Meltwater
• Salinity and stratification

(Siegert et al. 2003)
8
Life?

• Ecological Scenarios (Christner et al. 2003)
• Accreted Ice
• Heterotrophic
• Supported by Karl et al. (oligotrophic)
• DOC levels sufficient to support heterotrophic
  growth (Priscu et al. 1999)
• Chemolithotrophic
• Derive energy from the oxidation of inorganic
  compounds
• Geothermal input? (Siegert et al. 2001)

http//whyfiles.org/coolimages/images/csi/nur04506
.jpg
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Life?

• Studies of Accreted Ice
• Priscu et al. 1999
• Karl et al. 1999
• Microbes
• Preserved ecosystems in lake floor sediments?

(After Karl et al. 1999)
(Priscu et al. 1999)
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Planetary Studies

• Europa (Zotikov 2006)
• Drilling
• Sterilization
• Neoproterozic Snowball Earth (Siegert et al.
  2001)

http//www.stsci.edu/inr/thisweek1/thisweek/europ
a.gif
11
References

• Christner, B. C., G. Royston-Bishop, C. M.
  Foreman, B. R. Arnold, M. Tranter, K. A. Welch,
  W. B. Lyons, A. I. Tsapin, M. Studinger, J. C.
  Priscu. 2008. Limnological conditions in
  subglacial Lake Vostok, Antarctica. Limnology and
  Oceanography 51 (6) 2485-501.
• Kapitsa, A. P., J. K. Ridley, G. de Q. Robin, M.
  G. Siegert, I. A. Zotikov. 1996. A large deep
  freshwater lake beneath the ice of central East
  Antarctica. Nature (London) 381 (6584) 684-86.
• Mayer, C., K. Grosfeld, M. J. Siegert. 2003. The
  effect of salinity on water circulation within
  subglacial Lake Vostok. Geophysical Research
  Letters 30 (14) 1767.
• Oswald, G. K. A., G. de Q. Robin. 1973. Lakes
  Beneath the Antarctic Ice Sheet. Nature (London)
  245 (5423) 251-54.
• Siegert, M.J. 2000. The identification,
  examination and exploration of Antarctic
  subglacial laks. Science Progress 83 (3) 223-42.
  
• Siegert, M. J., J. C. Ellis-Evans, M. Tranter, C.
  Mayer, J. Petit, A. Salamantin, J. C. Priscu.
  2001. Physical, chemical and biological processes
  in Lake Vostok and other Antarctic subglacial
  lakes. Nature (London) 414 (6864) 603-09.

12
References

• Siegert, M.J., M. Tranter, C.J. Ellis-Evans, J.C.
  Priscu, W.B. Lyons. 2003. The hydrochemistry of
  Lake Vostok and the potential for life in
  Antarctic subglacial lakes. Hydrological
  Processes 17 795-814.
• Studinger, M., G.D. Karner, R.E Bell, V. Levin,
  A.A. Tikku, C.A. Raymond. 2003. Geophysical
  Models for the Tectonic Framework of the Lake
  Vostok Region, East Antarctica, Earth Planet
  Science Letters 216 663-77.
• Siegert, M. J. 2005. Reviewing the origin of
  subglacial Lake Vostok and its sensitivity to ice
  sheet changes. Progress in Physical Geography 29
  (2) 156-70.
• Thoma, M., C. Mayer, K. Grosfeld. 2008.
  Sensitivity of subglacial Lake Vostoks flow
  regime on environmental parameters. Earth and
  Planetary Science Letters 269 (1-2) 242-47.
• Zotikov, I. A. 2006. The Antarctic Subglacial
  Lake Vostok Glaciology, Biology and Planetology.
  Chichester, U.K. Praxis Publishing Ltd.