Hydrothermal explosion causes damage in area of Yellowstone National Park • Washington State Standard

A hydrothermal explosion in Yellowstone National Park damaged a boardwalk and sent debris several stories into the air Tuesday morning in the Biscuit Basin area northwest of Old Faithful, according to the scientist-in-charge at the U.S. Geological Survey’s Yellowstone Volcano Observatory.

The explosion, which Scientist-in-Charge Michael Poland said was a “small” one, happened around 10 a.m. Tuesday about 2.1 miles northwest of Old Faithful, likely in the Black Diamond Pool in Biscuit Basin, Poland said.

Poland said in an information statement early Tuesday afternoon there had so far been no injuries reported in the explosion.

Videos posted online by people who witnessed the explosion showed several people on the boardwalk close to where the explosion occurred, and videos of the aftermath show debris across the area and a damaged boardwalk.

Biscuit Basin’s parking lot and boardwalks are temporarily closed for safety; Yellowstone National Park geologists are investigating the explosion but say data shows no out-of-the-ordinary volcanic activity.

“Monitoring data show no changes in the Yellowstone region. Today’s explosion does not reflect activity within the volcanic system, which remains at normal background levels of activity,” Poland said in a statement. “Hydrothermal explosions like that of today are not a sign of impending volcanic eruptions, and they are not caused by magma rising towards the surface.”

He said these types of explosions happen when water quickly changes to steam underground and they are “relatively common” in Yellowstone National Park.

There was a similar explosion in Biscuit Bay in May 2009 and a smaller explosion in Norris Geyser Basin on April 15. Porkchop Geyser in Norris Geyser Basin exploded in 1989.

Hydrothermal explosions often send boiling water, steam, mud and rock into the air and can reach heights of up to 1.2 miles, according to the U.S. Geological Survey. It said in a 2018 report that large hydrothermal explosions happen on average every 700 years. At least 25 craters have been identified in the park that are at least 328 feet wide, according to the report.

“Although large hydrothermal explosions are rare events on a human time scale, the potential for additional future events of the sort in Yellowstone National Park is not insignificant,” the report says. “Based on the occurrence of large hydrothermal explosion events over the past 16,000 years, an explosion large enough to create a 100-meter (328-ft-) wide crater might be expected every few hundred years.

According to the National Park Service, Black Diamond Pool erupted black, murky water following an earthquake in July 2006 and saw “several explosive eruptions” in the days after, though eruptions have been “infrequent” since then. Its average temperature is 148.5 degrees Fahrenheit.

The public affairs office for Yellowstone National Park pointed the Daily Montanan to the news release from the Yellowstone Volcano Observatory and said no further information was immediately available early Tuesday afternoon.

The Yellowstone Volcano Observatory said it would release more information as it becomes available.

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