[Geysers] Lone Star Study

[TSBryan at aol.com]

Thank you, Carlton. I'd been thinking of a response, but you did great.  
(Seems like in the past few years, a simple study of geyser action is an 
"easy"  way to get published!)
 
Scott Bryan
 
 
In a message dated 7/22/2013 2:26:51 P.M. US Mountain Standard Time,  
cross at bmi.net writes:

This  article perpetuates a major fallacy about geysers.  Eruptions 
are not  caused by a buildup of pressure; they're caused by increasing 
temperature  and the formation of steam bubbles that reduce the pressure.

There are  two major concepts that explain geyser eruptions:  1) The 
static  pressure is determined by the depth below the water surface, 
and 2) The  boiling point increases as the pressure increases.  Most 
of us have  dived into a swimming pool and felt the pressure of the 
water as we go  deeper.  We also know that a pressure cooker will cook 
faster because  the water is hotter when it boils under pressure.

So, in quiet water,  the pressure will be the static pressure 
determined by the depth, and,  once the geyser reaches overflow, that 
pressure will remain constant at  all depths.  Now, consider a column 
of water.  The deeper water  can be hotter without boiling because the 
pressure at depth is  higher.  As a glob of water rises because of the 
overflow of the  geyser, the pressure on that glob will 
decrease.  Once the water  column has heated sufficiently, the water 
reaching a particular depth will  be hotter than the boiling point for 
that depth.  When it boils and  forms steam bubbles, the bubbles will 
expand and rise which then reduces  the pressure caused by the weight 
of the overlying water.  The  pressure drop allows more water to boil 
and the process becomes  self-sustaining.

Constrictions are often involved in geyser  plumbing.  What happens in 
a constriction is that the pressure drops  as the fluid moves 
faster.  Think about a hose that has a leak.   The faster the water 
flows through the hose, the less the water will  squirt out of the 
leak.  In a constriction, the smaller the passage  is, the faster the 
water will flow and the lower the pressure will  be.  Again, once the 
steam bubbles start to form, the weight of the  overlying water will 
decrease and the pressure will drop.  Thus, at a  constriction, there 
are two reasons why boiling will occur.  It's  likely that most 
geysers have significant constrictions, but a  constriction is not 
necessary for an eruption to occur.

Carlton  Cross


At 01:45 PM 7/21/2013, you wrote:
>Here is short  synopsis of a longer article about a study done 
>recently at Lone Star  Geyser. It quotes the longer study: The 
>Journal of Geophysical  Research: Solid Earth, June 19  edition.
>
>http://www.livescience.com/38299-yellowstone-lone-star-geyser.html
>
>Pat  Snyder
>_______________________________________________
>Geysers  mailing  list
>Geysers at lists.wallawalla.edu
>

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