Newest Volcano Notice Including Yellowstone

Summary

Yellowstone Caldera activity remains at background levels, with 52 located earthquakes in July (largest = M2.8). Deformation measurements indicate that the annual summertime pause in long-term caldera subsidence started in late May.  Two small eruptions of Black Diamond Pool in Biscuit Basin were recorded by a webcam on July 3 and July 14.

Recent Work and News

Sporadic minor eruptions continue at Steamboat Geyser in Norris Geyser Basin, but they have not reached an intensity that suggests a major eruption will occur soon.  There have only been 2 major eruptions of the geyser so far during 2025, indicating that the episode of frequent activity that started in 2018 is coming to a close.

The new webcam at Biscuit Basin, installed in mid-May 2025 to track activity at Black Diamond Pool (where a hydrothermal explosion occurred on July 23, 2024), continues to send static images to https://www.usgs.gov/media/webcams/biscuit-basin-webcam.  During July, the webcam captured two small eruptions from the pool, on July 3 at 8:18 p.m. MDT and on July 14 at 3:23 a.m. MDT.  Each eruption threw muddy water 20–30 feet (6–9 meters) into the air and lasted only a few seconds.

Also at Biscuit Basin, a new multi-parameter monitoring station was established in late July.  The station includes a GPS antenna to track ground movement, seismometer to measure ground shaking, and microphone array to record low-frequency sound waves.  Data from these sensors will soon be available via the Yellowstone Volcano Observatory website and other sources.

During the past month, field engineers from the University of Utah Seismograph Stations performed maintenance and upgrades on several seismic stations in the park and installed a new station near Slough Creek in the northeast part of the park.  Field engineers from the EarthScope Consortium were also in Yellowstone performing maintenance and upgrades on continuous GPS stations.
 

Seismicity

During July 2025, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, located 52 earthquakes in the Yellowstone National Park region. The largest event of the month was a micro earthquake of magnitude 2.8 located about 10 miles northeast of West Yellowstone, Montana, on July 30 at 3:10 a.m. MDT.

There were no swarms identified during the month of June.

Yellowstone earthquake activity remains at background levels.

Ground Deformation

Continuous GPS stations in Yellowstone Caldera continue to record the annual summertime pause in subsidence or transition to slight uplift, which is caused by seasonal changes related to snowmelt and groundwater conditions.  Since late May, the caldera has risen by about 1 cm (less than half an inch), which is superimposed on the overall trend of subsidence that has been ongoing since 2015–2016.

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