Winter operations, 1970-1971 / John C. Ayers, Norbert W. O'Hara, William L. Yocum.

of ridge ice contributes to the floe ice.
In addition to direct physical destruction by violent wave action, and to
undercutting and collapse of ridge portions during less violent wave conditions,
wave action throws bottom sand either directly over the ridge face or blows
sand up through blowholes. In both cases the sand is incorporated (along with
windblown beach sand) into the ridge by being covered by subsequent spray ice,
slush ice, or snow solidified by spray and freezing.
Regardless of its origin, sand incorporated in the ice acts as a dark body
and absorbs solar energy. Being warmed, it melts the underlying ice and settles
into it. As successive sand increments are added to the upper sand layer by
this process the total sand accumulated during the dark-body melting process
lies on the surface as a lag-concentrate. The more sand accumulated by this
process, the thicker and more continuous the surface sand layer becomes, and the
more effective it becomes as an accumulator of solar energy and consequently the
more effective it becomes as a melting agent of the underlying ice. Sand-melting
of ice continues in the ice ridges and lagoon ice even after other ridges or
lagoons further offshore have stopped wave action and deprived them of the means
of rejuvenation.
The total picture of ice ridges and lagoons is a dynamic and changing one.
Exterior ice fields, second outer ice barriers, and second lagoon ice are transient and apt to be carried away as the result of wave flexing and wind or current
pressure. Ridge C, the normal outer barrier of the shore ice structure, can be
broken up or breached but so long as the weather and the water remain sufficiently cold the rejuvenating processes will begin and restoration will be made.
Basically, the construction, maintenance, and destruction of the shore ice
structure is dynamic and changing. It is a system that bears within itself simultaneously the means of growth and the means of destruction. What goes on at

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