Re: Extinction scenarios

["James R. Cunningham" <jrccea@bellsouth.net>]

John Bois wrote:

> On Fri, 14 Aug 1998, James R. Cunningham wrote:
> > Also, sunsets 5 or 6
> > million times redder than the Krakatoa skys translate to coal-black skies 
> > for a
> > significant period.
>
> Apples and oranges.

True, Enever went through a justification process, then qualified it by 
assuming the
meteor impact was only 1% as efficient as Krakatoa at putting fines in the air, 
which
is another way of saying most of the other stuff was big enough to fall out 
quickly.
The recent Jupiter impact observations substantiate an expectation of  
significant
atmospheric opacity over a significant time span.

>  Is there evidence which demonstrates the grain-sizes
> of these two events were similar.

See above. Also, Enever references the photograph of the lunar dust cloud 
raised by
Lunik V.  Which settled back to the surface very quickly because of the lack of 
an
atmosphere.

> I would expect most material to fall
> out rather quickly no matter how much was initially launched into the
> atmosphere.

The big stuff will.  Little stuff doesn't.  Again, refer to the Jupiter impacts 
where
the material stayed in suspension while fighting 2.6 g's..

>  I'm just asking.  I would expect the suspension ability
> of the atmosphere to be non-linear, i.e., 6 million times more material
> doesn't mean 6 million times darker.

I agree, it doesn't.  It means opaque.  As Enever says, "did you ever read fine 
print
through even one hundredth of an inch of granite"?  I haven't, and probably 
won't,
give this subject the thought that Enever did, but he's done the best verbal
description I've ever seen of the effects and appearance of a large meteor 
impact,
and subsequent direct observations appear to bear him out in most detail.All the
best,
Jim