NetNews Usenet Archive 1992 #16/NN_1992_16.iso/spool/sci/environm/10038

Internet Message Format | 1992-07-26 | 3.6 KB

Path: sparky!uunet!ogicse!unmvax!mimbres.cs.unm.edu!nmt.edu!houle
From: [e-mail] (Paul Houle)
Newsgroups: sci.environment
Subject: Re: The Biggest Bomb on Earth
Message-ID: <[e-mail]>
Date: 25 Jul 92 19:59:35 GMT
Article-I.D.: nmt.1992Jul25.195935.23457
References: <[e-mail]> <[e-mail]>
Organization: New Mexico Tech
Lines: 57

In article <[e-mail]> mfriedma@uucp (Michael Friedman) writes:

>To prove it, I cahllenge Claire to put her money where her mouth is.
>Let's say $5,000.  The bet is on if we bomb Iraq again.  We'll let the
>net decide who wins.
>
>By the way, Claire, mind telling us what's prevented the gas from
>evaporating and dissipating?  And why none of the other fires set it
>off?

    Actually,  yesterday I did some looking in the CRC handbook to see
if there was any credibility in all in the idea of an oil lake exploding.
I remember reading that temperatures in the desert in Kuwait commonly reach
120 F,  which is about 50 degrees centigrade.  Of course,  an oil lake could
also affect microclimate,  probably increasing temperatures because of it's
low albedo.  But,  to make it simple,  let's just assume we have a lake
of oil at a temperature of 120 F.

    Crude oil is primarily a mixture of hydrocarbons,  although there are
also other impurities.  So,  I tried to estimate the vapor pressures of
different hydrocarbons.  All the hydrocarbons heavier than nonane would not
evaporate significantly.  Heptane would have a vapor pressure on the order
of 50-60 mm Hg.  If we put a sample of heptane in a box,  it would come to
equilibirum with the atmosphere in the box at somewhere around 7% by
volume.  I'm not sure,  but I think that the optimal air-fuel mixture for`
an FAE would be on the order of 5%.  Under still air conditions and
"equilibirum" with an infinite atmosphere,  a steady-state solution of
the diffusion equation would give us an exponential falloff with boundary
condition at the lake surface of about 7% heptane by volume.  So,  it
is not unreasonable that at certain times in the life of a crude oil
lake that both explosive and combustible levels of vapor could build up
under low wind conditions.

    In reality this is a really complicated problem.  The steady-state
solution isn't necessarily valid since the supply of volatiles in the oil
will blow away as time goes on.  The size of the lake makes a difference,
as the does the composition of the crude (I think that I read that Kuwaiti
crude is considered to be of very high quality since it contains a high
proportion of lighter hydrocarbons,  but I'm not sure of this.)  One
also needs to consider wind conditions and microclimate changes created
by the presense of the oil.  Even so,  I can't rule out that Claire might
be more-or-less right.  Fortunately,  the amount of oil in the explosive/
combustable layers would probably be a fraction of that in the slick...
Although it might set the lake on fire which would also be a problem.

    Regarding the stuff about FAEs sucking the oxygen out of lungs,
Claire didn't start this peice of disinformation.  I have a friend who
thinks that he knows everything about weapon systems who told me this too.

    Then again,  a 250-million barrel lake of oil is a pretty amazing
thing even if it isn't on the verge of exploding.  I'm sure that someone
out on the net (or maybe I'll do it if I get off my ass) can relate this
to,  say,  the amount of world oil consumption in a month and things like
that.  It does seem to me to be a bad ecological disaster;  completely
wiping out the biosphere around it,  and also evaporating,  releasing
hydrocarbons into the air.
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