Park staff assess the damage to Biscuit Basin boardwalks after hydrothermal explosion. NPS photo
July 23, 2024 – National Park Service officials report that on Tuesday, July 23, at about 10:19 A.M., a localized hydrothermal explosion occurred near Sapphire Pool in Biscuit Basin, located just north of Old Faithful.
Biscuit Basin, including the parking lot and boardwalks, are temporarily closed for safety reasons. The Grand Loop Road remains open.
No injuries were reported and the extent of damage is unknown at this time.
Park staff and staff from USGS will monitor conditions and reopen the area once deemed safe.
No other monitoring data show changes in the Yellowstone region. Today’s explosion does not reflect a change in the volcanic system, which remains at normal background levels of activity.
This is an evolving incident, and additional details will be shared as more facts are known.
Learn more about geology in Yellowstone.
View a joint statement between Yellowstone National Park and U.S. Geological Survey about the hydrothermal explosion below.
Yellowstone Volcano Observatory Information Statement
At around 10:00 A.M. MST on July 23, 2024, a small hydrothermal explosion occurred in Yellowstone National Park in the Biscuit Basin thermal area, about 2.1 miles (3.5 km) northwest of Old Faithful. Numerous videos of the event were recorded by visitors. The boardwalk was damaged, but there were no reports of injury. The explosion appears to have originated near Black Diamond Pool.
Biscuit Basin, including the parking lot and boardwalks, are temporary [sic] closed for visitor safety. The Grand Loop road remains open. Yellowstone National Park geologists are investigating the event.
Hydrothermal explosions occur when water suddenly flashes to steam underground, and they are relatively common in Yellowstone. For example, Porkchop Geyser, in Norris Geyser Basin, experienced an explosion in 1989, and a small event in Norris Geyser Basin was recorded by monitoring equipment on April 15, 2024. An explosion similar to that of today also occurred in Biscuit Basin on May 17, 2009.
More information about hydrothermal explosions is available at hydrothermal explosion.
Monitoring data show no changes in the Yellowstone region. Today’s explosion does not reflect activity within volcanic system, which remains at normal background levels of activity. 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.
Additional information will be provided as it becomes available.
The Yellowstone Volcano Observatory (YVO) provides long-term monitoring of volcanic and earthquake activity in the Yellowstone National Park region. Yellowstone is the site of the largest and most diverse collection of natural thermal features in the world and the first National Park. YVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.
YVO Member agencies: USGS, Yellowstone National Park, University of Utah, University of Wyoming, Montana State University, UNAVCO, Inc., Wyoming State Geological Survey, Montana Bureau of Mines and Geology, Idaho Geological Survey
Source & photos: NPS
