Guest
Hydrothermal explosions like the one at Biscuit Basin are more common than you might think in national parks, writes guest columnist Michael Poland. Shortly before 10 a.m. on July 23, a plume of hot water, mud and rock erupted from Black Diamond Pool in Yellowstone National Park’s Biscuit Basin, just about 2 miles northwest of Old Faithful. No early warning signs were detected by monitoring instruments. Dramatic video posted to social media showed a plume of water and rock fragments soaring about 600 feet into the air as people scrambled for safety. The explosion severely damaged nearby pavement, and the basin remains closed while geologists assess the activity. Fortunately, no one was hurt. Geologists examining the deposits have noted that the rocks ejected by the explosion consisted of glacial material, sandstone and siltstone, and gravel directly beneath the silica sinter that forms a thin layer on the surface. None of the rhyolite bedrock that exists about 175 feet below the surface (based on drill
