Re: air blowing out of an old mine

[David Bone <dbone@scnc.bas.k12.mi.us>]

My understanding of the workings of a geyser is that the water superheats
from the pressure above and when some of the overlying water is pushed
out, the superheated water flashes to steam to provide the force to eject
the rest of the water column.  This would not be the effect acting on the
air in the mine

Dave Bone                "Outside of a dog, a book is man's best friend
                          Inside of a dog it is too dark to read"-Groucho




On Wed, 16 Sep 1998, Herbert H Gottlieb wrote:

>  David Bone <dbone@scnc.bas.k12.mi.us> writes:
> > . Maybe the hot air from the bottom cools as it rises and expands but 
> > that doesn't explain why it would blow straight up into the 90 degree
> air 
> > of a hot summer day.  
>
> Perhaps the rising air in the mine can be compared with
> rising water and steam from a geyser.  As the water is heated 
> by the high temperatures (far above water's boiling point)
> below the surface it drives out the cool water near the surface
> with an almost explosive force.  The temperature of the 
> air above the surface is irrelevant.
>
> Herb Gottlieb from New York City
> (Where geysers errupt when water mains rupture)