Old Faithful remains a mainstay of Yellowstone National Park; even if you crave the sweeter charms of that park's vastly quieter backcountry, it's a rite of passage to first stand among the throngs of white t-shirted, fannypacked tourists and wait to see the geyser spew plumes of hot water and vapor. An appreciative crowd will start a chorus of oohs and aaahhs, momentarily cooled by wind-borne mist, and you can move on beyond the land of moose jams.
Eruptions of Old Faithful happen basically every 90 minutes, but the time between eruptions can last as short as 45 and as long as 125 minutes. Now, scientists from the U.S. Geological Survey think they may know where these variations come from: Annual rainfall patterns in the park have a large effect on the intervals between eruptions.
USGS researcher Shaul Hurwitz and his colleagues from Stanford University and Yellowstone National Park have discovered that changes of water supply to a geyser's underground plumbing may have a large influence on eruption intervals; that is, the time between eruptions. For example, geysers appear to lengthen and shorten their intervals on cycles that mimic annual dry and wet periods.
Multi-year precipitation records also strongly correlate with geyser behavior. Based on these results, the study proposes that an extended drought should result in longer intervals between eruptions, and perhaps even cessation of activity in some geysers. In contrast, in years with high precipitation, eruption intervals should be more frequent.
The study, co-commissioned by the National Park Service and the USGS, was just published in the June issue of the scientific journal Geology. Based on this research, scientists at Yellowstone may be able to eventually predict when Old Faithful will erupt with even greater accuracy.
This is fantastic news, as I always seem to arrive at Old Faithful at the beginning of the longest cycle of the day. In the near future, maybe I'll be able to call ahead and get a daily schedule for exact times of eruption. Now that's what I call national park service!
— Ted Alvarez