Yellowstone Caldera Chronicles is a weekly column written by scientists and collaborators of the Yellowstone Volcano Observatory. This week's contribution is from Annie Carlson, Research Coordinator at the Yellowstone Center for Resources, Yellowstone National Park.
Have you ever witnessed an Old Faithful Geyser eruption and wondered how it works? What hidden underground environment causes thousands of gallons of water to burst skyward? Why does the geyser behave so faithfully? And how does the geologic history of the Upper Geyser Basin play a role in the extraordinary geyser activity we see today? These questions are the topics of ongoing studies, and you might catch a glimpse of active researchers soon.
Old Faithful Geyser is the most famous geyser in the world. Millions of people have watched Old Faithful's remarkable eruptions, marveling as the water column climbs more than 100 feet into the air. Adding to the wonder, the geyser erupts predictably, roughly every hour to hour and a half. While many geysers go through periods of dormancy, Old Faithful has not taken a known break in activity for more than 140 years. For a natural thermal feature, this is astounding.
Past scientific research has provided clues to some of our burning questions about Old Faithful. In the early 1990s a team of scientists lowered a specially designed video camera into the underground conduit of the geyser. The camera went down nearly 50 feet before it encountered roiling hot water ascending from below. The footage (viewable on Youtube!) revealed a constriction in Old Faithful's conduit 22 feet down, which may trap steam and water and build pressure for a geyser eruption.
A more recent study utilized an array of small portable seismometers to map the ground beneath Old Faithful. The researchers discovered a reservoir below the ground several hundred feet west of the geyser that contains about 79 million gallons of hot water. As is often the case, discoveries like these prompt new scientific questions.
This November, several scientists will come together in the Upper Geyser Basin to collect samples and data. These researchers hail from the U.S. Geological Survey, the Universities of Wyoming, Utah, and New Hampshire, and Montana State University. They must wait to conduct their research until the interior park roads close to the public so as not to disturb visitors. This often makes for cold and snowy fieldwork conditions.
One group of scientists will collect silica sinters and other rock samples in order to determine their age, mineralogy, and whether they were deposited under glacial ice or subaerially. This group will also collect tree-ring samples to identify spatial and temporal patterns related to changing hydrothermal activity.
A second group will continue their investigations into the park's geohydrobiology, focusing on Old Faithful Geyser. They will take a variety of geophysical measurements around the geyser, such as electrical resistivity, nuclear magnetic resonance, and seismic refraction. They will also sample Old Faithful surface water for geochemistry, isotopes, and microbial communities.
A third group will retrieve the small portable seismometers that were deployed in response to the recent changes on Geyser Hill.
If you tune in to the Old Faithful webcam you might catch a glimpse of these researchers between Nov. 5 and 16. Please keep in mind that they have obtained permits from the National Park Service in order to conduct research and travel off-boardwalk in a thermal area. Their proposed methods have been reviewed, and we do not expect any damage to Old Faithful Geyser or other thermal features in the Upper Geyser Basin. We expect this research to contribute to our ever-expanding knowledge of and appreciation for Yellowstone's hydrothermal systems.
Tune in this week to have a look for yourself.