Yellowstone National Park has announced the discovery of a new thermal feature — a 13-foot baby blue hot spring in the Norris Geyser Basin.
In a Monday announcement, the U.S. Geological Survey (USGS) reports the new pool emerged sometime around Christmas and was first spotted in April.
The feature doesn’t have a name (and probably won’t), but it’s an exciting new addition to the most dynamic thermal basin in Yellowstone, officials said.
“I think this is a testament to the ability we have nowadays to see these sorts of things,” said Mike Poland, scientist in charge of the Yellowstone Volcano Observatory. “We're able to see the dynamic nature of these geyser basins on display in a way that hasn't been possible before.”
Silent Night
The pool was discovered in the Porcelain Basin area of Norris Geyser Basin near a spot that geologists colloquially refer to as “Tree Island.” Geologists spotted it during their first trip into the area April 10.
Using data recorded from high-resolution satellite imagery and acoustic sensors, Poland said they were able to pinpoint the pool’s formation to around Dec. 25, 2024.
“It wasn't there on Dec. 19, looks like it started to form by early January, and it was definitely there by early February,” he said.
What’s more interesting to geologists is how subtly this new pool emerged. Poland said the formation of this new hot spring was "subtle."
“It seems to have formed via a small explosion, but nothing particularly impressive in terms of how much material it put out or how much noise it made,” Poland said. “When you see a hole like this, you think it must have been a pretty impressive event, and there are some rocks scattered around the area that clearly flew out of the pool, but it's not something that created a lot of noise.”
Another hydrothermal explosion happened in Norris Geyser Basin at the nearby Porcelain Terrace in April 2024. Poland said that one was “much louder," registering on seismic stations more than 10 miles away.
Meanwhile, the event that led to the formation of this new pool didn’t register on any of Yellowstone’s seismic stations and barely registered on acoustic sensors. Both resulted in new features in Norris Basin, but with very different outcomes.
“The dramatic one that happened last year is basically a pit of busted up rock, whereas this one is this nice class of blue water pool,” he said.
Baby Blue
The new pool is 13 feet in diameter and filled with light blue “warm” water around 109 degrees. According to Poland, it’s showing all the signs of a classic hot spring.
“The water is warm, but not scalding hot,” he said. “There isn't any boiling coming from it. It seems to have filled with water, and now it’s just sitting there.”
That doesn’t mean the pool’s behavior won’t change in the future, especially in Norris Geyser Basin.
Yellowstone’s pools are infamous for changing their behavior over time, whether it’s caused by natural subterranean changes or human interference.
Most of Yellowstone’s thermal pools get their color from the thermophilic bacteria living in their water. According to Poland, the new pool’s baby blue color comes from the high amount of dissolved silica floating in the warm water.
Poland said the USGS and Yellowstone Volcano Observatory are keeping a close eye on the new pool to see what it might do. With the myriad tools at their disposal, it’s easier than ever to understand what’s happening in Yellowstone.
“There’s something special about working in the area and knowing it well enough,” he said. “Norris is incredibly dynamic, and there are always new features forming there.
“We spend a lot of time working there. So, coming across a new feature and doing the investigative work to see when it formed is pretty neat, but it’s also a testament to the technological advances we have in monitoring.”
Diamonds In The Rough
Hydrothermal explosions have been the hot issue in Yellowstone for ayear. On July 23, 2024, the largest hydrothermal explosion in recent years happened at Black Diamond Pool in Biscuit Basin.
Almost a year later, Black Diamond Pool has continued to be the object of intense scientific scrutiny. Several smaller events have been documented since the massive hydrothermal explosion last July.
“It might have even had a small burst overnight,” Poland said. “We didn't actually see anything because it was after sunset on Sunday, but we could tell from the camera images that the water level was rising, and we could see a temperature change at one point, shortly after midnight, on a temperature probe in the pool.”
Black Diamond Pool hasn’t been erupting regularly, but Poland said “explosive bursts” have been observed “every few days and weeks.”
The basin won’t reopen to the public until geologists have a good gauge of its current and future behavior.
Every day is exciting in Yellowstone National Park, but the advances in technology available to the USGS and the Yellowstone Volcano Observatory are making geologists giddy. This new hot spring in Norris Geyser Basin is just the latest example.
“Even though this feature had a really subtle emergence, we can actually constrain when and how it formed,” Poland said. “Thanks to high-resolution satellite data and some innovative ground-based monitoring, we have a more comprehensive way of looking at things. That's not something we've had the ability to do before.”
Andrew Rossi can be reached at arossi@cowboystatedaily.com.
