[time-nuts] disciplning natural phenomena

[Lux, Jim]

As I re-read Fleming's "You Only Live Twice" last night, which features 
a geyser that is "regulated" by a valve of some sort I was intrigued by 
this idea:

Can one discipline a geyser to an external source?

a) I assume there's some data somewhere on eruption timing - sure, Old 
Faithful is quite regular, sufficiently that they can say "the next 
eruption will occur at" and people will gather and watch it.  But what's 
the ADEV? As a kid in the early 70s, I didn't think to ask this 
question, and neither Allan nor Leeson seem to mention it in their 
papers from 1966.  There is a lot of variation in timing performance of 
various geysers, though.  Old Faithful *is* regular, and in a place 
where it's watchable.

b) Are periodic geysers actually regulatable ?- From the little I know 
about how they work, I would think the eruption frequency depends on 
things like the water temperature and flow. It's also possible that the 
valve in Fleming's novel is purely fictional, because it serves as part 
of a plot device at the end (much like closing off the safety valve on a 
boiler).

Or, are geysers an example of a chaotic system that is only seemingly 
regular in some sense? That is, it's not like a VCO, with a consistent 
and well defined relation between the control input and the period. 
Changing the control input may change the period in an unpredictable 
way. Some geysers stop working if the surrounding hydrology changes. Or 
is that simply that the Q of the oscillator is so high that it's easy to 
"get out of operating range".  That would be like trying to discipline a 
spurious parasitic oscillation in an amplifier.