On Mon, 15 Jan 2001 23:41:09 -0500 "Vandergraaf, Chuck"
<vandergraaft@aecl.ca> writes:
> Is it possible that the same principle caused the planes to sink deeper
into
> the ice? I don't know if the pressure of the planes was sufficiently
high
> to cause melting of the ice under the planes but there was lots of
> time.
Hi Chuck,
That's a great question.
First, the post of David Bowman indicates otherwise: "One thing one
might want to keep in mind here is the order of magnitude of the freezing
point depression of water--which happens to be about only 0.0075 deg
C/atm. This means that a local pressure in excess of 130 atm is
necessary to depress the freezing point by only 1 deg C."
As I'm sure you know, when water freezes it has enough force in expansion
to crack the steel block of an engine (as my son-in-law almost discovered
this winter). In order to reverse the process at sub-freezing
temperatures, a confining force greater than the expansion force would be
required to break the hexagonal structure of ice and cause it to melt.
But, perhaps ice remains somewhat plastic and is subject to "frozen
flow." This would be a nice experiment to run in a lab to see if a
weight with maybe 95% of 130 atm would deform solid ice with time and
sink into the ice. If it did, then maybe the effect of the plane's
weight in glacial ice over 50 years could be extrapolated.
Another factor to consider is the density of the plane, assuming the
plane remains filled with air. With the volume of empty fuel tanks and
the airspace in the wings (outside of the fuel tanks) and the fuselage, I
would think the plane would float in water. In fact, small planes "land
" on water with only those little floats on the water, so the entire
plane would have to be much lighter than water or ice. Therefore, the
plane would tend to float in ice unless the ice filled up the air spaces.
I think Kent Hovind said he had talked to one of the men who had
recovered the plane in 1992. I'll see if Kent can give me the name,
maybe we could talk with him.
Bill
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