Reactivated Yellowstone geyser isn't an indication of pending volcanic eruptions

Something rather strange has been going on in Yellowstone National Park. The park is home to some of the most famous geysers in the world, and in 2019 a geyser known as the Steamboat Geyser in the Norris Geyser Basin at the park erupted. That was notable because this particular geyser had its first documented activity in 1878 and has only erupted sporadically since then.The geyser once went 50 years without erupting. In 2018 Steamboat Geyser reactivated after going 3.5 years without activity. It erupted again in 2019. The reasons for its activity in recent years are unclear. Steamboat Geyser shoots water higher than any active geyser in the world.

When the geyser activated in 2018 after 3.5 years of lying dormant, speculation suggested it indicated a potential explosive volcanic eruption in the surrounding geyser basin known as hydrothermal explosions. Those explosions can throw mud, sand, and rocks in the air and release hot steam, potentially endangering lives. A similar hydrothermal explosion happened in New Zealand on White Island in 2019, killing 22 people.

Geoscientists studying geysers don't think the park is in for a hydrothermal explosion. They have discovered few indications of underground magma movement that would be a prerequisite to such an eruption. Geysers inside Yellowstone National Park are set just outside of the largest and most dynamic volcanic caldera in the US. However, there have been no major eruptions in the last 70,000 years.

Researchers found that while the ground around the Geiser rose and seismicity increased somewhat before the Geiser reactivated, and the area currently is radiating slightly more heat into the atmosphere, no other dormant geysers in the basin have restarted. The team also noted the temperature of groundwater propelling eruptions at Steamboat has not increased. No sequence of Steamboat eruptions, other than the one started in 2018, occurred after periods of high seismic activity. The researchers found no evidence that a large eruption is coming.