<html> <head> <meta content="text/html; charset=utf-8" http-equiv="Content-Type"> </head> <body bgcolor="#FFFFFF" text="#000000"> We saw 2 consecutive eruptions on our way out of the park July 9. Interval was 17 minutes, but the pool seemed to be draining after the second (we had line of sight to Vixen for another 15-20 minutes and know it didn't erupt again within that time frame). Durations were 3+ minutes on the first eruption and 5 for the second; both built to fairly good height---would estimate 20 feet on the largest bursts if you counted to the top droplet of water. This was all "other than expected" from the reports I've been reading and what was in the log book at Norris (most reports did seem to include series where the eruptions were 2-3 minutes apart). Both eruptions occurred from a full but not overflowing pool, but we did get the almost continuous stream of bubbles in the minute or so before each eruption. Actually, the pool oscillated a bit at about the mid-point of the interval, then dropped and settled shortly before the bubbles started. It's not much, but I hope it helps anyone who's plotting data! Karen Webb <div class="moz-cite-prefix">On 7/6/2016 3:09 PM, M.A. Bellingham wrote: </div> <blockquote cite="mid:CABfFJ5RLYCYbZ=HduiD8ns4USDdPAkoL5ZKA1C8AthxHRYokGg@mail.gmail.com" type="cite"> <pre wrap="">Hello Gazers - Late last fall I couldn't make sense of the Vixen intervals just before road closing, which continued through this spring. I set out to learn what I could to maximize my time there, and learn the pre-eruptive behavior so I wouldn't have to wait around for 90 minutes (like waiting for Vixen prior to Oct. 2013… first gurgle is X minutes until eruption, and so on). What I found was a very interesting pattern, which is still continuing, with some variants, as of July 4th. As far as I know, Vixen has not had cyclic behavior since 1984 (Paperiello, “Report on the Norris Geyser Basin for 1984”). It might have happened - - infrequent reports calling it “erratic” might be due to limited observations and not seeing the 'big picture'. We may never know; for example, a mention in 1927 states "some days quite dormant and others a spurting spit-fire." (I am going to continue looking at historic accounts with a new eye and see what I can find.) I myself have been guilty of only staying for a few hours and then leaving for Whirligig, but generally the behavior and intervals would remain consistent from week to week. Although Norris features change, once you figured it out, it was good for a while, so I do not think it has done this in the last two decades. If you know otherwise, I would be happy to be wrong and have more information! This activity "basically" includes a rest period as the pool slowly fills from low in the tube, followed by an eruption from a very very full platform. The longest rest-refill period in these last 2 weeks was about one hour (shorter than it was earlier in the season). This is followed by a group of "medium" intervals, say 20-30 minutes, shortening as we go along to, for example, 15, 12, 10, 8 minute intervals. At some point the bubbles indicating a pending eruption begin ASAP after the end of the previous and game on! Short intervals continue for quite a while, about 2-5 minutes apart, depending on duration. Some brief duration eruptions are in the same minute, others are of longer duration, but the similarity is that the restart action begins quickly after the end of the previous. All this time the pool is slowly lowering and the eruptions do not start from the full platform. In discussion with several gazers who have sat through this cycle with me, we haven't yet agreed on which is the start and which is the end of the cycle. That's a discussion about geyser series behavior that we can hash out… when the roads close!! At this point I have seen about 1200 eruptions this season, around 20 visits, with many “closed” sets. Statistically, I know that isn't huge, but it's definitely fun once you understand the pattern. Stop in and see it!! If you want to be helpful, getting data on the LONG intervals is, to me, more important than enjoying the frequent eruptions, but when those kick in, it is the fun reward for staying! Closed intervals are great, of course, but if you see just one (or none), a comment about the length of time it was NOT in eruption and the pool level on the platform while you were there would also be helpful. During past eruption-behavior changes, good observations on GeyserTimes have really helped narrow down the day (or in one case, half a day) of when dramatic changes occurred, even if the observer didn't stay long. Help if you can, it's for the historic record. Thanks. And PS! If you want to see this, I'd get down there, you never know how long it will last! It is Norris, after all. MA M.A. Bellingham <a class="moz-txt-link-abbreviated" href="mailto:mabellingham@gmail.com">mabellingham@gmail.com</a> _______________________________________________ Geysers mailing list <a class="moz-txt-link-abbreviated" href="mailto:Geysers@lists.wallawalla.edu">Geysers@lists.wallawalla.edu</a> <a class="moz-txt-link-freetext" href="https://lists.wallawalla.edu/mailman/listinfo/geysers">https://lists.wallawalla.edu/mailman/listinfo/geysers</a></pre> </blockquote> <hr style='border:none; color:#909090; background-color:#B0B0B0; height: 1px; width: 99%;' /> <table style='border-collapse:collapse;border:none;'> <tr> <td style='border:none;padding:0px 15px 0px 8px'> <a href="https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient"> <img border=0 src="http://static.avast.com/emails/avast-mail-stamp.png" alt="Avast logo" /> </a> </td> <td> This email has been checked for viruses by Avast antivirus software. <a href="https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient">www.avast.com</a> </td> </tr> </table> </body> </html>