Lesson 3/Learning Event 1
attraction exists between this supercooled water and ice crystals that form in larger voids. The
supercooled water flows to the ice crystals and solidifies on contact. The ice crystals grow and form an
ice lens (Figure 18). The lens grows until ice formations at a lower level elevation cut off the source of
water or until the temperature of the soil just below the surface of the ice formation rises above the
normal freezing point.
FIGURE 18. FORMATION OF ICE LENSES AT FROST LINE
For ice segregation to occur (in frost susceptible soil) a source of water must be available. The water
may come from the underlying ground, the water table, infiltration, an aquifer, or the water held within
voids of fine-grained soils (Figure 19).