[Rockhounds] The largest hydrothermal explosions the world has ever known

[Kreigh Tomaszewski]

While a full-scale volcanic eruption of a Yellowstone super volcano often
grabs the headlines and shows up in disaster movies; full-scale eruptions
are incredibly rare and unlikely to occur without advanced warning.
Hydrothermal explosions, on the other hand, are far more common and more
concerning than most people realize.

Speaking of the recent hydrothermal
<https://www.ksl.com/article/51077118/biscuit-basin-closed-in-yellowstone-national-park-after-massive-explosion>explosion
at Biscuit Basin
<https://www.ksl.com/article/51077118/biscuit-basin-closed-in-yellowstone-national-park-after-massive-explosion>
in
July, Michael Poland, head scientist at the Yellowstone Volcano
Observatory, said, "This was the thing that geologists were most worried
about — an explosion like this during the day, during the summer, in a
geyser basin that is heavily visited."

"It's always been sort of the most likely hazard to impact people in the
park — that, and a big earthquake," he said. "And I don't think it was that
well appreciated, prior to this event. But maybe it's better appreciated
now."

Just a few months before the Biscuit Basin explosion, Poland said
Yellowstone experienced another hydrothermal explosion in April, at Norris
Geyser Basin. But because it occurred during the transition from winter to
summer, no one was there to witness it in person. It was only discovered
when geologist located a newly formed crater in May, and then verified the
eruption using a U.S. Geological Survey monitoring station, which had been
installed in 2023.

USGS modeling data suggests hydrothermal explosions occur every year in
Yellowstone National Park but, compared to the Biscuit Basin explosion,
which sent water, steam and debris as high as 500 feet to 600 feet into the
air, most explosions are comparatively small, reaching heights between 6
and 20 feet
<https://www.usgs.gov/observatories/yvo/news/digging-history-hydrothermal-explosions-biscuit-basin>
.
Explosions on the scale of the July 23 Biscuit Basin event occur about
every one or two decades, according to Poland. But those often occur in the
backcountry, or in winter when no one is around to witness it, or be
injured, consequently.

https://www.ksl.com/article/51100381/the-largest-hydrothermal-explosions-the-world-has-ever-known