[Geysers] August 27 Giant details

[Bruce Jensen]

Tara, you have a real gift for describing these Giant eruptions - they
help me look forward to the day when I can witness one.  Thank you!

Bruce Jensen
************

--- Tara Cross <fanandmortar at hotmail.com> wrote:

> A message from Tara Cross <fanandmortar at hotmail.com>
> 
> My apologies for the delay in getting this sent out.
> 
> August 26
> 
> 0534 Grotto, electronic time
> 0733ie Giant hot period, d>2m.
> 0900 Bathtub, or "double bathtub," because the water came up and dropped
> twice.
> ~1400 Grotto off; d~8h30m.
> 1816 Giant hot period, d=9m56s.  Feather Satellite started 40s into the
> hot period.    Mastiff's boiling started about 45s into the hot period
> and was up and down for almost the entire duration, between flat at 3
> feet.  Some of the boiling was wide.  At around 6 minutes, there was a
> boil to 4 feet, but it quickly dropped back down.  Mastiff's runoff just
> barely covered India.  Cave bubbled to an inch or two.  80 seconds after
> Feather quit it had a restart that lasted 2 minutes.  While Feather was
> on fairly strong (and Satellite joined in for part of the restart), the
> water level in Giant was not very encouraging and the best it managed
> was a few drops to ¼ of the way up the cone.
> 
> All in all, it was a better hot period than I had expected, just 4 hours
> after the end of a mini-marathon (or whatever you prefer to call it).  I
> was actually quite encouraged that if the energy stayed on the South
> side of the platform and Grotto did not marathon again right away, that
> there could be an eruption in the next day or two.  However, since I did
> not expect a good hot period before dark and it was rather chilly, I
> didn’t go out to Giant for any subsequent hot periods on the 26th.  I
> also do not know when Grotto had its first eruption after the marathon.
> 
> August 27
> 
> I was the first gazer to check Giant in the morning.  It was only a few
> degrees above freezing when I headed out, and there was thick geyser fog
> over the entire geyser basin.  When I arrived at Grotto, I found it i.e.
> at 0700.  South Grotto Fountain was also i.e. and there was heavy steam
> coming from the pool around Grotto Fountain, so I surmised that Grotto
> had started 30-40 minutes earlier.
> 
> When I arrived at Giant Bijou was on strong with steam and Mastiff was
> depth charging.  It was doing this in spite of the lack of evidence of a
> strong period any time recently.  The edges of India were damp, but the
> majority of it was dry.  It was also dry in front of Feather and the
> Southwest Vents.  I surmised that it had been at least an hour since the
> last hot period, and that hot period couldn’t have been very strong.
> 
> Events then progressed as follows:
> 
> 0700ie Grotto
> 0700ie South Grotto Fountain
> 0743 Grotto off, but South Grotto Fountain still erupting (S.G.F. off by
> 0755)
> 0804 Giant hot period (d=2m24s).  SW 24s before Feather; F, SW, Mastiff
> light overflow.
> 0907 Bathtub; Mastiff rose and dropped twice and Feather overflowed.
> 1002 Giant hot period (d=33s).  Just Feather and SW Vents (which started
> before Feather) and no Mastiff overflow.
> 1058 Grotto Fountain, d=15m
> 1102 Grotto
> 1107 Footbath, water barely visible when standing on the railing.
> 
> At this point I reasoned that the next hot period had potential.  When
> the energy is on the south side of Giant's platform, Grotto tends to
> have fewer marathons and Giant has frequent, weak hot periods in between
> strong hot periods that come every 6-8 hours (or more, if Giant is
> getting ready to erupt).  It’s also common to see Bijou on strong and
> depth charging from Mastiff in between the weak hot periods.
> 
> The next time Bijou paused, I saw water rising very quickly in Mastiff. 
> The Southwest Vents started right away, 27 seconds before Feather began
> at 1131.  Feather Satellite joined in rather quickly, just 25 seconds
> after Feather, along with Rust.  During the first 4 minutes of the hot
> period, Mastiff was up and down, but mostly flat.  Most boiling was 6
> inches to 1 foot high, but there was one boil to about 2 feet.  Mastiff
> put out moderate overflow.
> 
> Then, around the 5-minute mark, Mastiff's boiling increased to 2-3 feet
> and got wider.  Cave began to bubble more vigorously, reaching about 3
> inches high.  Mastiff's surging became essentially steady, reaching as
> much as 4 feet high, and as wide as it was tall.  By this time Cave was
> boiling to 6 inches.  I thought it might go into eruption, but it never
> did.  (Apparently, though I have absolutely no memory of it, there was a
> point in the hot period when I accidentally called Cave to 2-4 feet when
> I meant Mastiff, but folks said it got them moving quicker so it's all
> good in the end.)
> 
> Mastiff was up and down again, a few inches to 2-3 feet.  It was about 7
> minutes into the hot period when the surging suddenly increased
> dramatically, first to 4-5 feet, then 6 feet, then a very wide surge to
> 7-8 feet.  My calls, which had admittedly been rather blasé up to that
> point, got a lot more urgent, and I even added "You'd better get down
> here!" for people who were still on their way.
> 
> The surging dropped down to 4-5 feet, then back down to 2-3 feet, but
> remained steady.  By this time I had decided it would be a good idea to
> dig my video camera out of my backpack.  Mastiff continued to boil from
> a few inches to 3 feet until about 8 ½ minutes into the hot period, when
> it abruptly went flat and then dropped.  Feather and Feather Satellite
> began to weaken for about 15 seconds, but then they kept on erupting. 
> Bijou came on right away, and soon Feather was back at full strength.
> 
> Our attention then turned to Giant, where there was very little water in
> the cone at first.  Then low vertical water could be seen, about 9 ½
> minutes after the start of Feather.  The surges built from only a foot
> above the rim to a third of the way up the cone, then two thirds, then
> the top of the cone.  Then the surging dropped down again and built
> again, until there was a large surge over the top of the cone.  On the
> next surge, Giant burst to 30 feet.  (The entire progression took about
> 2 minutes.)
> 
> GIANT, 1143!!!!
> 
> The column lifted slowly, reaching up towards the late morning sun
> against a bright blue sky.  Then the water came crashing down, landing
> on and thoroughly soaking the right-hand side of the monkey cage (nearly
> everyone had fled to the main boardwalk, except for Julie, who was up
> against the railing).  Spikes of water poked out the top to an estimated
> height of 160 feet.  The eruption was very angled, aided by the wind
> which blew the steam towards Round Spring.  The column was beautifully
> backlit for most of the eruption.
> 
> Since Grand was in its window, many visitors were able to see Giant, as
> well as a fine crowd of gazers, some of whom were seeing their first
> Giant start (congratulations to all).  Most people headed back up to
> Grand after the eruption began to wane but I waited to the end of the
> water, which was at 100 minutes exactly.  The interval was 8d10h22m.
> 
> (Had the interval been 8d10h23m, I would have officially entered the
> Twilight Zone.  On August 27, 2001, I saw Beehive at 1107.  Afterwards I
> decided to head to the Lower Basin to try to catch Fountain.  I was
> pulling into the Fountain Paint Pot Parking lot as Fountain was called. 
> The time was 1143.  I did not find out until later that Giant had
> started at 1144.  I'll just say that this eruption felt a little bit
> like payback.)
> 
> --Tara Cross
> fanandmortar at hotmail.com
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