[Geysers] Lone Star Study

[Pat Snyder]

Thank you for clarifying this, Carlton.

Pat Snyder

On Jul 22, 2013, at 12:11 PM, Carlton Cross wrote:

> 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
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> 
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