About midway through the summer we made a list of things we wanted to be sure to see or do before departing in September. Seeing as many of the significant geysers erupt as possible was high on the list. There are 14,000 thermal features in Yellowstone. I’m not sure how many of them are geysers but just in the Upper Geyser Basin near Old Faithful there are approximately 145 geysers. The eruptions of five of them can be predicted with relative accuracy to +/- 2 hours. Some erupt as frequently as every 90 minutes—others only every few days. Steamboat Geyser, the worlds largest last erupted in 2005 and some have not erupted since the early 1900s.
One predictable geyser that erupts approximately every 8-9 hours is Grand Geyser located about ½ mile from Old Faithful. Grand erupts in a spectacular display of steamy and watery fireworks. Yesterday afternoon the forecast eruption window was between 4:20 pm and 8:20 pm. We arrived there and found a seat with the wind and sun to our backs. A crowd had already formed and visitors from a sampling of states and countries waited patiently and watched the almost choreographed sequence of events unfold. We were fortunate to find ourselves in the midst of informative “Geyser Gazers” and rangers who were most willing to provide commentary. Geyser Gazers are a group of hobbyists who have turned analysis of the eruption sequence of each geyser into an intricate data collection process. The geyser gazers around us were from as far away as Virginia and as close as Wyoming and Idaho. Each with personal hand held radios set to channel 4/5 they keep listeners, including the park service, informed of geyser activities.
Like many geysers, Grand Geyser is connected to other geysers. The observed activity at one is often an indicator of impending activity at another. Grand is connected to Turban Geyser and Vent Geysers. As the window to eruption of Grand approaches, Turban begins a regular series of eruptions every 20 minutes. The Grand Geyser pool fills and drains with each eruption of Turban. Turban’s eruption appears like little more than some serious boiling. During its most violent eruptions, only it shoots scalding hot water about three feet into the air. With each eruption of Turban the Geyser Gazers wait with baited breath, hoping that the water level in the Grand Geyser Pool remains full. The drop in the pool’s level at the end of Turban’s eruption signals the beginning of another 20 minute wait for the next eruption. Grand’s eruption always coincides with a Turban eruption.
Over and over again at 20 minute intervals we watched as the pool level dropped exposing island like ridges of geyserite that are exposed anytime the pool is not completely full. After approximately 6 or 7 of these 20 minute cycles we saw the change. The pool dropped slightly and then continued to rise—ever so slowly submerging the geyserite ridges. Someone claimed to have seen waves in the pool – an indication that an eruption was eminent. The most experienced Geyser Gazer in the crowd picked up her radio and signaled to geyser gazers across the entire Upper Basin that there were waves in Grand. Then the pool began to boil followed by an explosive rocketing of hot water and steam perhaps 150 feet into the air.
The applause of the crowd showed the approval with natures geologic show which continued for 9 minutes during which Turban continued its boiling and Vent coincidentally shot its stream of water skyward adding to the spectacle. The early evening sun shining through the condensing steam added a beautiful rainbow to the spectacle.
The geyser gazers hopped for an early halt to the breathtaking display. The early halt in the action seems to allow the underground chamber to rearm for a second and more explosive eruption. We were in luck and the break came followed shortly there after by the second and larger eruption. In years past this cycle would continue for as many as 14 times. Now days one eruption is the norm with two or three being special events.
The show ended with Grand and Turban becoming silent. Vent would continue for quite some time. We applauded again as if to say thanks to Mother Earth for the entertainment and all wondered off in different directions. On our way out of the basin we were rewarded with a timely eruption of Old Faithful. For many, Old Faithful is the only geyser activity they will witness during their stay at Yellowstone. Old Faithful is a wonder but it truly pales in comparison to Grand, Lone Star, Great Fountain, or many others.
I would like to continue with more on our visit to Boiling River, the Roosevelt Arch at Mammoth or the recent significant wildlife sightings but I’ll save that for later.
Life sure is good!
