Biscuit Basin was named for the unusual biscuit-like deposits that used to surround its Sapphire Pool. Following the 1959 Hebgen Lake earthquake, Sapphire Pool erupted, and the “biscuits” were blown away. Previous to this week it last erupted in 1991. Jewel Geyser erupts every 7-10 minutes.
On Tuesday, July 23, 2024, an eruption occurred on at approximately 10:00 AM MDT. It was a hydrothermal explosion, which happens when hot water in a volcano system flashes into steam in a confined area. The explosion was small in size, but it was powerful enough to destroy a nearby boardwalk and eject grapefruit-sized rocks tens to hundreds of feet from the source.
The explosion was largely directed to the northeast toward the Firehole River, and the largest blocks of debris fell in that direction. The Yellowstone Volcano Observatory scientists have cautioned that given the recent changes to the hydrothermal plumbing system, small explosions of boiling water from this area in Biscuit Basin continue to be possible over the coming days to months.
The National Park Service will likely keep Biscuit Basin closed until Yellowstone’s geologists thoroughly understand its post-eruption behavior. It’s too early to determine if and how the eruption of the Black Diamond Pool has permanently changed Biscuit Basin, but it probably won’t be the same as it was before.
“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,” USGC wrote.
(Heads Up!) Biscuit Basin in Yellowstone National Park temporarily closed due to hydrothermal explosion. More info: https://t.co/tcDR8oRNSx pic.twitter.com/YP7CkwNrQR
— Yellowstone National Park (@YellowstoneNPS) July 23, 2024