For scientists who want to understand why some geysers erupt relatively regularly and others don’t, Yellowstone National Park offers a valuable testing ground. Researchers at the University of Utah have closely observed these famous streams of water and steam in the air and have now managed to imagine the plumbing system of the highest in the world. According to the team, these findings could form the basis for more accurate monitoring systems that predict exactly when these powerful geysers might transition into more active phases.
The new research is based on decades of observation of the geological activity of Yellowstone National Park by scientists from the University of Utah who were presented with a unique opportunity in the recent and ongoing eruption of Steamboat, the world’s tallest geyser reaching heights of 360 feet. 110 m). This follows just two more periods of steamboat activity in recorded history in the 1960s and 1980s, a pattern that is in stark contrast to the park’s Old Faithful geyser, which erupts about 20 times a day.
“We scientists don’t really know what keeps a geyser from erupting regularly, like Old Faithful, or erratically, like Steamboat,” says study author Fan-Chi Lin. “The underground plumbing structure likely controls the eruption properties of a geyser. This was the first time that we were able to map the sanitary structure of a geyser to a depth of more than 100 m. “
Scientists were able to create these images of Steamboat’s underground structures using football-sized seismometers, 50 of which were placed on the ground around the geyser to record seismic activity during the 2018 and 2019 events, which are used to create an image of the structures subsurface in a process likened to using multiple x-rays to make a CT scan of the inside of the body.
Two angles of the plumbing system under the steamboat geyser (solid star) and the cistern spring (solid square)
This indicated that the pipelines for the Steamboat Geyser extend to a depth of at least 140 m and revealed new findings between these channels and cracks and the nearby cistern spring. Since this body of water drains when Steamboat erupts, it was believed that there was a direct underground connection between the two, although the pictures show that it isn’t actually.
“This finding excludes the assumption that the two features are connected with an open pipe at least in the upper 140 meters,” says Sin-Mei Wu.
What is more likely is that the two are connected, but only through small pores or fractures in the rock that the team’s methodology failed to capture. A better understanding of the relationship between the source and the geyser could help the team model how the cistern can shape cycles of eruptions, as well as longer-term monitoring of seismic activity, especially when Steamboat enters quieter phases.
“We now have a basis for what steamboat eruptive activity looks like,” says Lin. “When it gets less active in the future, we can use our seismic sensors again and get an overview of what inactive periods look like. We can then continuously monitor data coming from real-time seismic stations running Steamboat and assess whether they look like one or the other, and get real-time analysis of when it looks like it is moving into a more active phase. “
The research was published in the Journal of Geophysical Research.
Source: University of Utah