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Yellowstone volcano: ‘Increased risk’ warning after scientists pinpoint ‘magma intrusion’ #Yellowstone #Magma #USA

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YELLOWSTONE researchers have warned there is an “increased risk of hydrothermal explosion” at Steamboat Geyser after pinpointing a body of magma that “intruded” below Norris Geyser Basin years ago.

Scientists used GPS data to model what may have occurred below the surface to explain why an area near the basin has been inflating and deflating by several inches in erratic bursts for the past two decades. Their research, published in the Journal of Geophysical Research, revealed a body of magma had “intruded” beneath Norris in the Nineties. As the fluid got stuck and pressure built up, the ground would rise, and when the fluids were able to escape elsewhere, the ground deflated.

The paper, published in January, reads: “Recent activity has provided new insights into the causes of surface deformation in and around the Yellowstone Caldera, a topic that has been debated since the discovery of caldera floor uplift more than four decades ago.

“An episode of unusually rapid uplift centred near Norris Geyser Basin along the north caldera rim began in late 2013 and continued until an earthquake on March 30, 2014, thereafter, uplift abruptly switched to subsidence.

“Split at rates of several centimetres per year resumed in 2016 and continued at least through to the end of 2018.

“Modelling of GPS and interferometric synthetic aperture radar data suggests an evolving process of deep magma intrusion during 1996–2001.”

Today, the researchers believe magma-derived fluids could sit close to the surface, just a mile or so below the ground.

The study added: “The depth of shallow volatile accumulation appears to have shallowed from the 2014 to the 2016 deformation episode.

“Frequent eruptions of Steamboat Geyser since March 2018 are likely a surface manifestation of this ongoing process.

“Hydrothermal explosion features are prominent in the Norris Geyser Basin area, and the apparent shallow nature of the volatile accumulation implies an increased risk of hydrothermal explosions.”

Co-author Daniel Dzurisin told National Geographic on Friday: “In all likelihood, Norris has been a centre of deformation for a very long time.”

The new research does not indicate that the supervolcano is any closer to erupting.

Instead, these geologic movements may help explain why the park’s Steamboat Geyser, the world’s tallest active geyser, has been erupting at a record-breaking pace since March 2018.

While the threat of a supereruption remains a reality, the USGS has previously put minds at ease regarding “overdue” claims.

Yellowstone Volcano Observatory’s Scientists-in-Charge Jacob Lowenstern said in 2014: “When you see people claiming it’s overdue, usually the numbers they come up with say the last eruption was 640,000 years ago, but it erupts every 600,000 years.

“But, in fact, if you average the eruption intervals, there’s 2.1 million to 1.3 million and then another 640,000 years ago.

“If you average those numbers you come up with something that’s over 700,000 years.

“So, in reality, even if you tried to make this argument, it wouldn’t be overdue for another 70,000 years.”

Courtesy of express.co.uk

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