[Geysers] RE: Giantess Big boils

[Gordon Bower]

I'd be very interested in hearing some other responses to these questions too. My own experience includes a lot of time on Geyser Hill but not all that much experience with Giantess itself.

How often are they? Highly variable. When the wind is calm, anything from one an hour up to boiling for one minute out of every five. When it's windy, they generally don't happen.

How tall are they? Usually well under a meter, but big and noisy. The last few Great Fountain boils before the one that starts the eruption, or the medium-sized Crested Pool boils (see below) are a fair comparison. 

Do they have any relation to Giantess erupting? There are people who think they do. Personally, I think not, except in the very general sense than eruptions are possible if boils are happening.

The one Giantess start that I was on the Hill for started with no warning at all. One incredibly loud and low-pitched bang, that I felt in my knees and stomach as well as hearing. By the time I looked up a half second later, there was a wall of water about six inches deep coming down all sides of the mound. (The only thing remotely similar that I've heard is the last thump from Deep Blue in the Kaleidoscope group before it erupts - but deep blue is preceded by several weaker thumps first.) The two other Giantess starts that I was in the upper basin but not on the hill for, I hadn't seen anything remarkable in the way of boils that same day or even that same week.

My take on it is that Giantess boils and starts are a lot like Crested Pool eruptions. Crested Pool does two distinct things when the wind is calm. Most commonly, it has big rolling boils that raise several square feet of the pool surface a foot or two upwards, accompanied by a loud roaring sound. These begin and end gradually over the course of several seconds. Crested's less common big eruptions start with no warning at all; the water leaps instantly to full height (sometimes 3 feet, sometimes over your head), and then boils furiously as it subsides. Sort of like a very frothy version of a blue bubble. At Crested, you can be guaranteed that if it takes several seconds to build up to a 2-foot boil, it *won't* continue building to 6 feet. I interpret Giantess boils similarly - a sign that it is hot enough for an eruption sometime, but that whatever attempt at an eruption there may have been has already failed. 

GRB



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