Newest Volcano Notice Including Yellowstone

Summary

Yellowstone Caldera activity remains at background levels, with 251 located earthquakes in November (largest = M3.2). Deformation measurements indicate no significant changes in surface displacement patterns since the summer.

Recent Work and News

At least two small eruptions occurred at Black Diamond Pool in Biscuit Basin, site of a hydrothermal explosion in 2024. The eruptions were captured by camera views and infrasound (acoustic) monitoring on November 22 and 29. Minor eruptions of Steamboat Geyser in Norris Geyser Basin remain sporadic, indicating that a major eruption is unlikely anytime soon.  There have only been 2 major eruptions of the during 2025, and the period of frequent activity that started in 2018 has probably ended.

Seismicity

During November 2025, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, located 251 earthquakes in the Yellowstone National Park region. The largest event of the month was a minor earthquake of magnitude 3.2 located about 14 miles south-southwest of Mammoth Hot Springs in Yellowstone National Park on November 9 at 5:00 p.m. MST.

November seismicity in Yellowstone was marked by three swarms:

1. An area of ongoing seismicity that began in late September continued through November, adding 70 earthquakes to the sequence approximately 14 miles south-southwest of Mammoth Hot Springs in Yellowstone National Park. The largest November earthquake (described above) is in this sequence.

2. A swarm of 105 earthquakes occurred approximately 16 miles west-northwest of Lake in Yellowstone National Park during November 2–30. The largest earthquake in the sequence was a magnitude 2.5 on November 5 at 7:25 p.m. MST.

3. A swarm of 11 earthquakes took place approximately 13 miles northeast of West Yellowstone, Montana, during November 26–27. The largest earthquake in the sequence was a magnitude 2.0 on November 27 at 2:45 a.m. MST.

Earthquake activity in Yellowstone is slightly above background levels.

Ground Deformation

Continuous GPS stations in Yellowstone Caldera recorded little net deformation over the past month, suggesting that the seasonal summertime pause in subsidence or transition to slight uplift may not be over just yet.  There has also been no net deformation in the area of Norris Geyser Basin since mid September.  Many GPS stations in the region showed spurious signals at the end of November due to winter weather 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)