Incident and immediate response
Yellowstone National Park’s Biscuit Basin area is temporarily closed following a hydrothermal explosion on Tuesday morning, according to park officials. The closure, which includes the parking lot and boardwalks, was implemented for safety reasons. No injuries were reported from the incident, which occurred near the Sapphire Pool around 10 a.m. local time.
Nature of hydrothermal explosions
The US Geological Survey (USGS) describes hydrothermal explosions as “violent and dramatic events resulting in the rapid ejection of boiling water, steam, mud, and rock fragments.” These explosions occur when shallow interconnected reservoirs of fluids at or near the boiling point transition rapidly to steam if the pressure drops. This transition results in significant expansion, blowing apart surrounding rocks and ejecting debris.
Yellowstone has experienced such explosions in the past. A notable event occurred at Porkchop Geyser in Norris Geyser Basin in 1989. More recently, a smaller explosion was recorded in Norris Geyser Basin on April 15, 2024. Biscuit Basin also experienced a similar explosion on May 17, 2009.
Current situation and monitoring
Today’s explosion does not indicate an imminent volcanic eruption. The USGS and park officials emphasized that “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.” They added that hydrothermal explosions are not a sign of impending volcanic eruptions and are not caused by rising magma.
Long-term outlook
Large hydrothermal explosions occur on average every 700 years. Although rare, the potential for future events in Yellowstone is significant. According to the USGS, based on the occurrence of large hydrothermal explosion events over the past 16,000 years, an explosion large enough to create a 328-foot-wide crater might be expected every few hundred years.
