Reconstructed geyser does not predict Yellowstone volcanic eruptions, research shows

When Yellowstone National Park’s Steamboat Geyser – which burns water higher than any active geyser in the world – re-emerged in 2018 after three and a half years of secrecy, some maintained that out that it was a blow of explosive volcanic eruptions that could be inside the surrounding geyser basin. The so-called hydrothermal explosions can throw mud, sand and rocks into the air and release hot steam, endangering lives; such an explosion on the White Island in New Zealand in December 2019 killed 22 people.

A new study by geoscientists studying geysers throws cold water on that idea, finding very few signs of underground magma movement that would be necessary for blasting. The geysers sit just outside the country ‘s largest and most vibrant volcanic caldera, but no major eruption has occurred in the last 70,000 years.

“Hydrothermal explosions – essentially hot water exploding because it interacts with hot rock – are one of the biggest hazards in Yellowstone,” said Michael Manga, professor of earth and planetary science at the University of California, Berkeley , and the study review. senior author. “The reason they’re a problem is that they’re very difficult to predict; it’s not clear if there’s any pre-runner that would allow you to give a warning.”

He and his team found that although the ground around the geyser rose and seismicity increased slightly before the geyser reactivated and the area is currently radiating a little more heat into it. to the atmosphere, other humiliating geysers in the basin have not resumed, and the temperature of the groundwater removes that steamer explosion has not increased. Also, a series of steamer explosions occurred only the one that started in 2018 after periods of high seismic activity.

“We will not find evidence of a major explosion coming. I think that’s an important takeaway,” he said.

The study will be published this week in Proceedings of the National Academy of Sciences.

Manga, which studied geysers around the world and created some in its own lab, teamed up with its colleagues to answer three key questions about Steamboat Geyser: Why Rebuild It? Why is his time so variable, ranging from 3 to 17 days? and Why is it pouring so high?

The team found answers to two of these questions. By comparing the height of columns of 11 different geysers in the United States, Russia, Iceland and Chile with the approximate depth of the water reservoir from which their explosions emanate, they found that the deeper the reservoir, the higher the jet explosion. Geyser has the tallest column of a steamer, with a reservoir about 25 meters (82 feet) underground – up to 115 meters, or 377 feet – while two geysers measuring manga in Chile were among the largest. lower – explosions about a meter (3 feet) high from reservoirs 2 and 5 meters underground.

“What you are really doing is filling up a carrier, it will reach an emergency point, you will leave it empty and then you will run out of water that can explode to fill it again, “he said. “The deeper you go, the higher the pressure. The higher the pressure, the higher the boiling temperature. And the hotter the water, the more energy it will be and the higher an geyser. “

To investigate the reasons for the Steamboat Geyser variability, the team collected records related to 109 explosions going back to reactivation in 2018. The records included weather flow data and currents, seismometer and ground deformation readings, and observations by geyser enthusiasts. They also looked at previous active and resting periods of Steamboat and nine other Yellowstone geysers, and ground surface thermal emission data from the Norris Geyser Geyser.

They concluded that changes in rainfall and snowmelt may have been due to part of the variable time, and possibly for the variable period of other geysers as well. In spring and early summer, with snow and melting water, the pressure of the groundwater pushes more water into the underground reservoir, providing more hot water for more frequent bursts. . During the winter, with less rain, lower groundwater pressure replenishes the reservoir more slowly, leading to longer intervals between eruptions. Because the water pushed into the reservoir comes from even deeper than the reservoir, the water is decades or centuries old before erupting back to the surface, he said.

In October, members of the Manga team demonstrated the devastating effects of water shortages and thirst on geysers. They showed that the famous old Faithful Geyser Yellowstone stopped exploding completely for about 100 years in the 13th and 14th centuries, based on a radiocarbon date of mineral pine trees that grew around the geyser while it was asleep. . The water is usually too alkaline and the temperature too high for trees to grow near active geysers. The hibernation period coincided with a prolonged warm, dry period across the western U.S. known as the Medieval Climate Irregularity, which may have plagued several Native American civilizations. in the West.

“Climate change is going to affect geysers in the future,” Manga said.

Manga and its team could not figure out why Steamboat Geyser started again on March 15, 2018, after three years and 193 days of inactivity, although the geyser is notorious for being long more variable than Old Faithful, which usually goes around every 90 minutes. They could not find conclusive evidence that a new magma rising under the gheyser caused a resurgence.

They may need to be revitalized with changes in the internal crane, he said. Geysers apparently need three components: heat, water and rocks made of silica – silicon dioxide. Since the hot water in geysers constantly disperses and replenishes silica – every time a Steamboat Geyser explodes, it will take up about 200 kilograms, or 440 pounds of loose silica . Some of this silica is deposited underground and could alter the plumbing system under the geyser. These changes could stop it temporarily or restart an explosion if the pipe is recycled, he said.

Manga has experimented with geysers in its lab to understand why they explode from time to time, and at least in the lab, it seems to be caused by loops or side chambers. in the pipe that catches steam bubbles dripping out, heating the water column upwards until all the water is boiled from the top down, exploding into a column water and steam.

Studies of water eruptions from geysers could provide insight into hot rock debris from volcanoes, he said.

“We’re asking very simple questions and it’s a bit embarrassing that we can’t answer them, because it means there are fundamental processes on Earth that we don’t fully understand,” Manga said. “One of the reasons we argue is that we need to study geysers, if we can’t understand and explain how geysers explode, our hope is to do the same for magma. much lower. “

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The research, led by UC Berkeley graduate student and first author Mara Reed, was the result of a collaboration that began in one of the annual summer workshops set up by the Collaborative Institute for Dynamic Research Earth, no CIDER. Other co-authors are Carolina Munoz-Saez from the University of Chile and Rice University in Texas, Sahand Hajimirza from Rice University, Sin-Mei Wu from Utah University, Anna Barth from Columbia University in New York, Társilo Girona from the University of Alaska , Majid Rasht-Behesht of Brown University in Rhode Island, Erin White of Yellowstone National Park in Wyoming, Marianne Karplus of the University of Texas and Shaul Hurwitz of the U.S. Geological Survey of California.