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    Ice sinking

    John Newton (John_Newton@eaur.wnyric.org)
    Wed, 5 Mar 1997 12:54:17 -0500

    I've watched various stages of ice out on rivers in New York State and on a
    large lake in the Adirondacks. Occasionally large chunks of ice will get shoved
    under others especially in rivers but the ice never sinks. With the current, the
    river ice tends to go out all at once. This causes many problems because it
    often gets hung up at bridges causing ice dams and consequently flooding.

    On lakes the ice tends to decay. At first there may be some partial melting that
    leaves long vertical "needles" of ice about 1 cm in diameter. It kind of looks
    like those metal pads of needles from museums used for making hand prints or

    What often happens on lakes is that the water level rises due to runoff thereby
    enlarging the surface area of the lake. This allows the smaller ice pack-frozen
    on a smaller surface area-to get blown around. Big chunks get pushed up on shore
    and the ice begins to break up because of the mechanic stress of being shoved

    Finally, when the ice pack is broken up and floating around pretty easily, the
    current will flush it down the river or it will just melt. Usually a lake will
    clear in one day once the pack size and temperature are right. It would be fun
    to correlate the surface area of the ice with air and water temperatures to get
    an idea about how to predict ice out.