On July 23, 2024, a powerful explosion occurred in Yellowstone National Park (YNP). The explosion, known as a hydrothermal explosion, happens when hot water and steam build up beneath the Earth’s surface. The hot fluids are trapped under the weight of the rocks and soil. When the pressure below becomes so great that the ground above cannot hold back the pressure, the pressure is suddenly released in a powerful blast.

This hydrothermal explosion threw rocks, mud, and steam over 70 meters (230 feet) from the source, and the blast was one of the largest recorded in the last 150 years in YNP. Scientists are studying what generated this explosion.

To do this, we are using detailed maps of the explosion site and cores from the 1960s that were drilled nearby. The cores show what kinds of rock were beneath the surface before the explosion, and we can use them to test the strength of the rocks to calculate the explosion energy.

This research helps us understand where, how, and why hydrothermal explosions happen in Yellowstone and around the world. We’re studying these blasts to keep visitors and Park buildings safe.