[Geysers] Webcam up in testing phase/ Grand

[jacross]

>Question for the masses:  What causes Thumps?  Some of us were having a
>discussion about steam explosions, steam implosions, and so on.

If hot steam bubbles get shot into cooler water they will condense.  Because 
the walls of the bubble are all headed inward they collide when the bubble 
disappears completely, making a concussion.

Also, you can get water hammers.  Steam moves through the geyser's plumbing 
faster than liquid water.  When a bubble moves through a constriction the 
column speeds up.  When the liquid water behind the bubble hits the 
constriction, the column slows down.  This process can get violent, resulting 
in loud booming sounds.

You can make your own steam concussions by placing an overturned funnel into a 
pot of cold water on the stove and then turning on the heat.  The water under 
the funnel will boil before the rest of the water does.  The steam bubbles 
will be shot out of the narrow end of the funnel and into the cooler water in 
the pot, making a humorous motor-like sound.  Smaller funnels do this better 
than larger ones.  It's best if you weight the funnel with something to keep 
it from rising off the bottom of the pot.

Jeff Cross
jacross at lamar.colostate.edu