[Geysers] Three geysers of note

[jacross]

I suspect that most changes in geyser activity are caused entirely by changes 
in the subsurface water and heat flow patterns, not by changes in the plumbing 
system.

Why do I say this?

Changes in flow patterns are reversible.  Thus, geyser like Plume, Giant, Fan 
and Mortar, etc. can enter dormant phases and then recover to erupt on 
precisely the same patterns as before.

Changes in the plumbing systems (blowing out constrictions, plugging channels, 
etc.) are not reversible.  Typically these involve the expulsion of sand, 
gravel, or larger blocks of sinter.  The formation of Plume's lower (largest) 
vent, the destruction of the former "Pathetic Little Hole," post-1959 Sapphire 
Pool, all represent permanent, irreversible changes.

Jeff Cross
jacross at lamar.colostate.edu

>I have been thinking about Echinus and there are a couple of questions I have 
to throw out-- seems like this geyser currently has plenty of water but (?) 
has gradually lost its heat source-- Or is it possible that it has damaged 
itself like Excelsior and Monarch are speculated to have done to 
themselves?... I wondered this since Norris is the hottest basin in the Park 
and is likely to still have plenty of heat.  <snip>
>    Mario Durrant
>
>    **************
>    Quite a number of years ago we ran into a ranger on a visit to Norris, at 
the time when Echinus was first having it's problems. He said that there was a 
new feature above Echinus that had a very, very low ph- low even for Norris. 
It was running off down into Echinus' pool, and his theory was that the 
acidity was eating away Echinus' throat, thus robbing it of it's ability to 
build pressure to erupt.