“Kablooey!”

This is how experts from the U.S. Geological Survey depicted a muddy eruption that occurred at Black Diamond Pool in Yellowstone National Park on Saturday morning.

In a video shared by the USGS on social media, mud can be seen shooting up and out of the pool shortly before 9:23 a.m. The event took place in Biscuit Basin, a location nestled between popular attractions like Old Faithful and Grand Prismatic.

Previous eruptions have been mostly audible rather than visible, as they often occurred at night or when the camera lens was blocked by ice.

The Black Diamond Pool was also the site of a significant hydrothermal explosion in July 2024, which hurled rocks and mud several hundred feet into the air and caused damage to a nearby boardwalk. This incident led to the area’s closure to ensure visitor safety due to the risk of further hazardous events.

So-called dirty eruptions reaching up to 40 feet (about 12 meters) have occurred sporadically since then.

Researchers installed a new camera and a seismic and acoustic monitoring station this summer, and they say the instruments, along with temperature sensors maintained by the Yellowstone National Park Geology Program, can better detect and characterize the eruptions.

The Yellowstone Volcano Observatory webcam at Black Diamond Pool didn’t disappoint Saturday.

“We got a nice clear view of one of these dirty eruptions under bright blue skies with the surroundings covered in snow (ah, winter in Yellowstone!),” USGS Volcanoes said on social media, noting that it was a great example of the kind of activity that has been happening at the spot over the past 19 months.

Experts say there is no real pattern to the eruptions at the pool and no precursors.

Park officials say Yellowstone preserves the most extraordinary collection of hot springs, geysers, mud pots and fumaroles on Earth. More than 10,000 hydrothermal features are found within the park, over 500 of them geysers.