Yellowstone National Park in the United States is the country’s first national park, renowned for its geothermal resources, including the famous Old Faithful geyser. Recently, geologists in the park’s basin discovered a newly formed 4-meter-wide large hole with milky blue spring water, adding another geothermal feature to the park.
The United States Geological Survey stated that geologists in Yellowstone Park conducted routine maintenance of temperature recording stations in the Norris Geyser Basin on April 10. This was their first visit to the area since last autumn.
They were surprised to find a newly appeared blue spring water pool on the west side of vegetation informally known as “Tree Island.” The pool has a diameter of about 4 meters (13 feet) and a temperature of approximately 43 degrees Celsius (109 degrees Fahrenheit), with the water surface about 30 centimeters (1 foot) from the pool’s edge.
Surrounding the pool, they also found numerous small stones with a diameter of 30 centimeters (1 foot) covered in light gray, fine sandy mud.
The agency indicated that this geothermal pool likely formed during a series of minor eruptive events between late December 2024 and early February 2025. Such eruptions in the area are not unexpected as similar events have occurred several times in the past few decades. The Norris Geyser Basin may be the most dynamic area in Yellowstone Park.
High-resolution satellite images show that the newly discovered hole was not present as of December 19 last year, but by January 6 this year, a depression had already formed. By February 13, the hole was filled with water.
The monitoring station installed in Yellowstone Park in 2023 can detect geophysical data related to eruptions, potentially recording more geothermal explosions.
For example, in July 2024, a hole appeared near the Biscuit Basin close to Old Faithful geyser due to a single hydrothermal explosive event.
The new hole discovered near “Tree Island” appears to have slowly formed starting around Christmas 2024, showcasing various forms of geothermal feature evolution. Some geothermal features form during brief and intense change processes, while others form through slower processes.
Yellowstone Park harbors a complex and expansive underground volcanic system. The park is under comprehensive monitoring by the Geological Survey and the Yellowstone Volcano Observatory.