Yellowstone National Park officials closed Biscuit Basin on Tuesday following a hydrothermal explosion that caused significant damage to a boardwalk and launched debris several stories into the air. The explosion occurred near Sapphire Pool, just north of Old Faithful, at approximately 10:19 a.m., according to a post on the park’s official Facebook page.
BREAKING: There was just a huge eruption at Yellowstone National Park.
pic.twitter.com/n6LYNHZ2bp— Creepy.org (@creepydotorg) July 23, 2024
Michael Poland, Scientist-in-Charge at the U.S. Geological Survey’s Yellowstone Volcano Observatory, described the incident as a “small” hydrothermal explosion. Despite its relatively small scale, the blast damaged nearby infrastructure and temporarily closed Biscuit Basin and its parking lots for safety reasons. Fortunately, no injuries were reported.
Videos posted online by witnesses showed people on the boardwalk close to where the explosion occurred, with subsequent footage capturing debris scattered across the area and significant damage to the boardwalk. The park staff, along with the USGS, are actively monitoring the situation and will reopen Biscuit Basin once it is deemed safe.
In an information statement released early Tuesday afternoon, Poland emphasized that there were no indications of abnormal 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,” he stated. “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.”
What is a Hydrothermal Explosion?
Hydrothermal explosions are described as “violent and dramatic events” by the United States Geological Survey (USGS). These explosions can reach incredible mile-high heights and spew boiling water, steam, mud, and rock fragments more than two miles out from the epicenter.
“Hydrothermal explosions occur where shallow interconnected reservoirs of fluids with temperatures at or near the boiling point underlie thermal fields,” the USGS explained. “These fluids can rapidly transition to steam if the pressure suddenly drops. Since vapor molecules take up much more space than liquid molecules, the transition to steam results in a significant expansion and blows apart surrounding rocks and ejects debris.”
These types of explosions are relatively common in Yellowstone National Park, typically occurring within the Yellowstone Caldera and along the Norris-Mammoth tectonic corridor in Montana. Past events include a similar explosion in Biscuit Basin in May 2009 and a smaller one in Norris Geyser Basin on April 15. Porkchop Geyser in Norris Geyser Basin also experienced a notable explosion in 1989.
Hydrothermal explosions can propel boiling water, steam, mud, and rock into the air, with some eruptions reaching heights of up to 1.2 miles. According to the USGS, large hydrothermal explosions occur approximately every 700 years on average. The park contains at least 25 identified craters, each at least 328 feet wide, formed by such explosions.
The National Park Service (NPS) provided additional context about the Black Diamond Pool, which erupted black, murky water following an earthquake in July 2006 and experienced several explosive eruptions in the days that followed. However, eruptions have been infrequent since then. The pool’s average temperature is 148.5 degrees Fahrenheit.
Yellowstone National Park’s public affairs office referred inquiries to the Yellowstone Volcano Observatory’s news release and stated that no further information was immediately available. The Yellowstone Volcano Observatory will release more details as they become available.
Hydrothermal explosions are the most likely explosive hazard from the Yellowstone Volcano, highlighting the dynamic and ever-changing nature of the park’s geothermal features.
For further updates, please refer to the Yellowstone Volcano Observatory’s statements and the National Park Service.
