Study of Steamboat Geyser also finds relationship between column height and reservoir depth.
When, after being inactive for three and a half years, the Yellowstone National Park Steamboat Geyser – which shoots water higher than any other active geyser in the world – reawakened in 2018, some suggested that it was a harbinger of potential violent volcanic eruptions in the nearby geyser basin.
These so-called hydrothermal explosions can hurl mud, sand and rock into the air and unleash hot steam, endangering human lives; 22 people were killed in December 2019 by one such explosion on White Island in New Zealand.
A recent research by geoscientists researching geysers throws cold water on that theory, finding no evidence of the movement of subsurface magma, which would be a requirement for an eruption.
The geysers are situated just outside the country’s largest and most active volcanic caldera, but no significant eruptions have occurred in the last 70,000 years.
“Hydrothermal explosions – basically hot water exploding because it comes into contact with hot rock – are one of the biggest hazards in Yellowstone,”Hydrothermal explosions – basically hot water exploding because it comes into contact with hot rock – are one of the greatest dangers in Yellowstone. “The reason they’re problematic is that they’re very hard to predict; it’s not clear if there are any precursors that would allow a warning to be given.”
He and his team found that although the ground around the geyser rose and seismicity increased somewhat until the geyser was reactivated and the region is currently radiating slightly more heat into the atmosphere, no other inactive geysers were restarted in the basin and there was no rise in the temperature of the groundwater fuelling the eruptions of Steamboat.
Furthermore, after periods of high seismic activity, no episode of Steamboat eruptions other than the one that started in 2018 occurred.
We have found no proof that a major eruption is imminent.
I think that’s a significant outcome,’ he said.
The thesis will be published in the Proceedings of the National Academy of Sciences this week.
Manga, who researched geysers around the world and developed several in his own laboratory, set out to address three key questions about the Steamboat Geyser with his colleagues: Why did it reawaken? Why is its period so unpredictable, varying between 3 and 17 days? And why is it shooting up so high?
On two of these questions, the team found answers.
They found that the deeper the reservoir, the higher the eruption jet, by comparing the column heights of 11 separate geysers in the U.S., Russia, Iceland and Chile with the approximate depth of the water reservoir from which their eruptions originate. The Steamboat Geyser has the highest column, up to 115 meters or 377 feet, with a reservoir about 25 meters underground, while two Manga geysers measured in Chile were among the lowest, with eruptions about one meter high from reservoirs 2 and 5 meters underground.
He said, “What you’re really doing is you’re filling a reservoir, it reaches a critical point, you empty it and then you run out of fluid to erupt until it fills up again,” And the deeper you go, the greater the pressure.
The higher the pressure, the greater the temperature of the boil.
And the colder the water, the higher the energy it has, the higher the geyser.
To investigate the explanations for Steamboat Geyser’s instability, the team collected records of 109 eruptions dating back to its reactivation in 2018.
Weather and flow data, seismometer and ground deformation measurements, and observations from geyser fans were included in the records.
They also looked at Steamboat and nine other Yellowstone geysers for previous active and inactive periods, as well as Norris Geyser Basin ground surface thermal emission results.
They concluded that changes in precipitation and snowmelt are likely responsible for part of the variable duration, and probably for the variable period of other geysers.
With melting snow and rain, surface water pressure forces more water into the underground reservoir in spring and early summer, providing more hot water that erupts more often.
The lower groundwater pressure fills the reservoir more slowly in winter, when there is less space, resulting in longer times between eruptions.
The water is decades or centuries old until it erupts back to the surface, because the water being forced into the reservoir comes from areas much deeper than the reservoir,