[Geysers] Geyser Report 8/22-8/23 -- Activity of Atomizer Geyser

[Lynn Stephens]

THIS POST IS FOR THE PERSONAL USE OF THE SUBSCRIBERS TO THIS LISTSERV AND IS NOT TO BE REPRODUCED

FOR ANY OTHER PURPOSE, INCLUDING PUBLICATION IN THE SPUT.

 

(Note to editors, Tara, and Ben--I will incorporate appropriate data and analysis from this post in my article on geyser activity for the October Sput.)
 

> Date: Tue, 25 Aug 2009 11:49:04 -0600
> From: caros at xmission.com
> To: geysers at lists.wallawalla.edu
> Subject: Re: [Geysers] Geyser Report 8/22-8/23
> 
> We reported in a series of Atomizer minors beginning with what we are 
> sure was the first minor while we waited out Artemesia on the 22nd. We 
> noticed as we left (unfortunately just missing F&M, but we had a child 
> to get home to) that neither made the log book (not sure why Art is 
> there and Atom isn't, as we turned them in at the same time). 

 

While I had my grandchildren with me, I did not go to the Visitor Center to check the logbook.  When I went to there last night, the following information had been entered for August 22--Atomizer minors 15:08, 16:40, 18:44, major 20:08.  In my mailbox was a note with the Artemisia duration plus two additional Atomizer minors--12:44 and 14:15, which I added to the logbook.  (I did not change the 1844 to 18:45.)

 

Anyway, 
> had a question for the more experienced Atomizer watchers, We had a 
> consistent 90 minutes between minors till the interval between the 3rd 
> and 4th minor, which was two hours. Each minor was preceded by 2-4 
> episodes of good overflow (what I call water "sheeting the cone") and 
> the later ones would have small surges as if an eruption might be about 
> to start. These happened in the neighborhood of 7-13 minutes apart and 
> started about half an hour before the actual eruption. The last minor 
> we observed, which had excellent (50-60 feet) height and a duration of 
> about 90 seconds, behaved like it might do a quick comeback major. 
> Then the steam bumps started. By the time Artemesia with its 28 minute 
> duration finished, a storm was coming in, it was getting dark, and we 
> were wondering if *all* the minors had been 90, then 120 minutes apart, 
> if we might be looking at a 3 hour wait for the major (gut feeling was 
> that the next one would be the major despite notes I've seen about 6-8 
> minors before the major). Love Atomizer, but not quite that much.

 

I don't know whether your definition of "behaved like it might do a quick comeback major" matches my definition.  My definition of post-eruptive splashing that looks like it might build to a quick comeback major (then either does or does not) is:  About five minutes after the eruption ends, Atomizer starts having small (usually) splashes with a few drops of water rising above the level of the cone.  These sporadic splashes continue for another 2 to 15 minutes before the activity either builds to a major eruption or the activity ceases.  On August 16, 2003, I observed a minor that was followed by audible gurgling and splashing for 12 minutes, and the next event was a major 1h38m later.  This may be similar to what you saw at 18:44--a minor followed by splashing, which was then followed by the major at 20:08, 1h24m later.

 

I have personally never seen more than 5 minors in a series.  In personal communications, Dave Leeking has told me that his statement "there are a half dozen or more minor eruptions during the interval leading up to the major" in his article about Atomizer in Transactions IV is not correct.  He said he was in a hurry to get the article finished, the focus of the article was on intervals between major eruptions, and he hurriedly added the section on the minor eruptions but he does not believe his statement was correct.

 

Looking at the data in the logbook and looking at data from my Atomizer article in Transactions IX:

                      Interval Between Minor

                              August 22                     Lynn's maximum in 2003        

Minor #1 to #2               91 min                             101 min                               

Minor #2 to #3               85 min                             84 min                                

Minor #3 to #4               2h05m                             2h05m                                  

#4 to major                    1h24m                        not calculated

 

> Anyway, wondered if anyone could comment on the longer minors with 
> the multiple episodes of overflow that seemed to delay the minors? In 
> know Dave and Kyle had been out a day earlier and seen a very normal 
> progression including a quick comeback major. My only experience with 
> this sheeting the cone/no eruption thing is very early in the action 
> before the first minor really occurs and after that if you see overflow 
> and bubbling, you get an eruption. (I even remember Rocco telling me 
> once upon a time that some gazers felt justified calling that phenomenon 
> the first minor.)

 

My experience with the sheeting the cone/no eruption is that this can occur before any or all of the minor eruptions,

not just before the first or first and second minors.  I have also seen this happen before the major.  The water level comes up, floods the cone, there imay or may not be bubbling action, then the water level drops and it takes a few minutes for the water level to recover before the next eruptive event.  Since this can happen before any eruptive event in the Atomizer series, I do not consider the phenomenon a minor eruption.

 

Earlier this summer someone asked a few questions about statistics on the Atomizer "quick comeback" major eruptions.  I don't have access to the articles Dave Leeking and I wrote in the Sput about statistics for the 1990s and later.  Here are some of the statistics from my Transactions article:

 

                               Quick Comeback      Total Number of observations       

1988                            3 (50%)                        6

1989                            5 (55.6%)                     9

1990                            4 (25.0%)                    16

2003                           11 (35.5%)                    31  

 

Number of minors    Number of cases              Quick Comeback

       3                       2                                  2 (100%)

       4                      10                                 6  (60%)

       5                       8                                  0

   Unknown                11                                 3  (27%)

 

Total                        31                                11 (35.5%)       

 

Lynn Stephens

 

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