HR: 08:30h
AN: C51C-03    [Abstracts]
TI: Ice Lenses in Colloidal Clays
AU: * Peppin, S
EM: stephen.peppin@yale.edu
AF: Department of Geology and Geophysics, Yale University 210 Whitney Ave, New Haven, CT 06511, United States
AU: Wettlaufer, J
EM: john.wettlaufer@yale.edu
AF: Department of Geology and Geophysics, Yale University 210 Whitney Ave, New Haven, CT 06511, United States
AB: A mechanism for the formation of ice lenses in colloidal clays is proposed based on an instability of the ice-clay interface. A mathematical model of freezing saturated montmorillonite is developed which predicts that, given freezing conditions typical of the field, the clay can become thermodynamically supercooled in the same sense as a binary solution such as salt water. A stability analysis predicts that in this case the ice-clay interface is unstable to the formation of a mixed-phase region composed of ice lenses and unfrozen clay. Experimental evidence in support of the theory is discussed and a continuum model of the mixed-phase region is proposed.
DE: 0704 Seasonally frozen ground
DE: 0706 Active layer
DE: 0762 Mass balance (1218, 1223)
DE: 0764 Energy balance
DE: 0766 Thermodynamics (1011, 3611, 8411)
SC: Cryosphere [C]
MN: 2007 Fall Meeting