Title Sensitivity of subglacial Lake Vostok's flow regime on environmental parameters
Author Thoma, M.; Mayer, C.; Grosfeld, K.
Author Affil Thoma, M., Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Federal Republic of Germany. Other: Bayerische Akademie der Wissenschaften, Federal Republic of Germany
Source Earth and Planetary Science Letters, 269(1-2), p.242-247, . Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012- 821X
Publication Date May 15, 2008
Notes In English. 47 refs. Ant. Acc. No: 84590. CRREL Acc. No: 62006647
Index Terms buoyancy; freezing; freezing rate; temperature gradients; glacial geology; ice; ice sheets; lakes; lake ice; melting; meltwater; models; salinity; temperature; thickness; Antarctica--Lake Vostok; Antarctica; circulation; depth; geothermal gradient; heat flow; International Polar Year 2007-08; IPY 2007-08 Research Publications; Lake Vostok; numerical models; rates; subglacial lakes; three-dimensional models
Abstract Subglacial lakes provide unique habitats, but the exact nature of physical and geochemical conditions are still a matter of debate and await direct sampling of water. Due to its isolation from external atmospheric forcing other environmental parameters influence the flow characteristics within the lake. In this study we use an improved treatment of the physical processes at the ice-water boundary interface to identify and quantify the impact of (1) the geothermal heat flux, (2) the heat flux from the lake into the ice, (3) the influence of the salinity of the lake water, and (4) the ice thickness on the size of the freezing area and the freeze/melt rates. We show that the modelled basal mass imbalance (that is the produced melt water minus the re-frozen water) depends on the geothermal heating as well as the heat flux into the ice. The circulation and the temperature distribution within subglacial Lake Vostok are rather stable against variations of geothermal heat flux, heat flux into the ice sheet, salinity of the lake, and small changes of the ice thickness above the lake. However, the flow regime for any subglacial lake with less than 2000 m ice thickness above, will be substantially different from those that experience higher pressures. This is because the buoyancy-temperature relationship reverses at this depth.
URL http://hdl.handle.net/10.1016/j.epsl.2008.02.023
Publication Type journal article
Record ID 286565