USGS Volcano Notice - DOI-USGS-YVO-2026-11-02T16:05:12+00:00

Yellowstone Caldera activity remains at background levels, with 66 located earthquakes in October (largest = M2.0). Deformation measurements indicate no significant uplift or subsidence of the caldera or north caldera rim for the past several months. Giant Geyser, in Upper Geyser Basin, erupted three times in October.

Recent Work and News

Hydrothermal activity in Yellowstone National Park during the month of October included an eruption of Echinus Geyser (Norris Geyser Basin) on October 26.  Giant Geyser (Upper Geyser Basin)—the second tallest geyser in the park—erupted on October 5, 13, and 22.  In addition, the small pool of hot water that formed via collapse in Biscuit Basin after the June 13, 2026, hydrothermal explosion had at least two small eruptions.  Steamboat Geyser, in Norris Geyser Basin, was characterized by minor eruptions and has only had one major eruption thus far in 2026.

Seismicity

During October 2026, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, located 66 earthquakes in the Yellowstone National Park region. The largest event of the month was a micro earthquake of magnitude 2.0 located about 15 miles south of West Thumb, Yellowstone National Park, on October 4 at 5:32 p.m. MDT.

There were no swarms identified during October.

Earthquake activity in Yellowstone is at background levels.

Ground Deformation

Data from continuous GPS stations indicate little net deformation of the caldera or north caldera regions over the past several months.  Subtle variations in ground motion are probably caused by seasonal changes, especially in groundwater conditions.

An example of GPS data can be found at http://www.unavco.org/instrumentation/networks/status/pbo/data/NRWY (click on Static Plots / Cleaned)