An aqueous thermal eruption in Yellowstone National Park has caused significant damage to a boardwalk and propelled detritus several stories high, according to the chief scientist at the U.S. Geological Survey’s Yellowstone Volcano Observatory. The incident occurred Tuesday morning in the Biscuit Basin vicinity, northwest of the iconic Old Faithful geyser.
This eruption, described as “minor” by Scientist-in-Charge Michael Poland, transpired around 10 a.m., approximately 2.1 miles from Old Faithful, likely originating from the Black Diamond Pool in Biscuit Basin. Fortunately, no injuries were reported.
Eyewitnesses captured footage of the eruption, showing individuals on the boardwalk in close proximity to the event. Subsequent images depict the area strewn with debris and the boardwalk visibly damaged.
For safety reasons, the parking area and boardwalks at Biscuit Basin have been temporarily closed. Yellowstone National Park geologists are currently investigating the eruption, but preliminary data indicates no unusual volcanic activity.
“Monitoring data reveals no significant changes in the Yellowstone region. Today’s hydrothermal eruption does not indicate increased volcanic activity; the system remains at its usual baseline,” Poland explained. He emphasized that such hydrothermal explosions are not precursors to volcanic eruptions and are not caused by ascending magma.
Poland further elaborated that these explosions occur when subterranean water rapidly transitions into steam, a phenomenon relatively common in Yellowstone. Similar events have been documented, including an eruption at Biscuit Basin in May 2009 and another at Norris Geyser Basin on April 15. Porkchop Geyser in Norris Geyser Basin also experienced a significant eruption in 1989.
Hydrothermal eruptions can project boiling water, steam, mud, and rocks into the air, with some debris reaching altitudes of up to 1.2 miles. According to a 2018 report by the U.S. Geological Survey, large hydrothermal explosions occur approximately every 700 years. The report identified at least 25 craters in the park, each at least 328 feet in diameter.
“While large hydrothermal explosions are infrequent on a human timescale, the possibility of future events of this nature in Yellowstone National Park cannot be discounted,” the report states. Based on past occurrences over the last 16,000 years, a hydrothermal explosion large enough to create a 100-meter (328-foot) wide crater could be expected every few hundred years.
The National Park Service noted that Black Diamond Pool experienced eruptions of black, turbid water following an earthquake in July 2006, with several explosive events occurring in the subsequent days, though such eruptions have been rare since then. The pool’s average temperature is approximately 148.5 degrees Fahrenheit.
The Yellowstone National Park public affairs office referred inquiries to the Yellowstone Volcano Observatory’s news release, stating that no further information was available early Tuesday afternoon.
The Yellowstone Volcano Observatory plans to provide additional details as they become available.
