Winter Operations : March 1970 / Norbert W. O'Hara ... [et al.].

The west side of the lake was devoid of ice. There was little or no ice
around the Zion plant site, the Oak Creek plant, Milwaukee, and the Port
21
Washington plant.
Sand in the ice.
The objective of this cruise was to try to obtain evidence as the means by
which sand is incorporated into the ice. Of particular interest in this connection
was the possibility that shore-ice blocks leaving shore during breakup might carry
substantial amounts of sand on their undersides, and that overturning of the blocks
during melting or fragmentation might expose to view sand layers of some thickness.
Alternatively, waves breaking against an ice edge might throw sand onto the ice
surface where it then became covered by more ice. We hear vaguely of "ball ice"
that is reported to roll along the bottom; whether it exists we do not know, and
the present study is unsuited to provide information on this matter.
In the present study we have seen no evidence indicative of ice-hotto.r
carrying of sand. All the sand seen in shore ice or ice floes ci(,K ini this crluis;
was in thin strata incorporated in the ice. These strata were dense enough to
impart a sand-color, but not so dense -,cs to prevent the ice underneath from being
seen. They could well have been formed by waves tossing suspended sand onto tihe
shore ice. In fact on 18 March in front of the Cook plant there was a notch iLn
the shore ice and a scattering of sand lay on the ice behind the notch.
We believe that this cruise has shown a widespread occurrence of the wavetossed sand phenomena, for many ice floes showed scattered-sand strata as the
surface ice melted, see Slides 4-10, 4-14, 5-3, 6-12, 6-15 and others. Wave-tossed
sand in the top of the ice bluff is clearly evident in Slide 7-16, and sand above
water in the lower part of the ice bluff is evident in Slides 2-20 and 2-21. These
ice bluffs were still fast to shore and were being sectioned by melting at the face.

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