USGS Volcano Notice - DOI-USGS-YVO-2025-06-02T16:54:47+00:00

Summary

Yellowstone Caldera activity remains at background levels, with 119 located earthquakes in May (largest = M2.7). Deformation measurements indicate a small amount of caldera subsidence since early October.  On May 31 at 8:39 p.m. MDT a small eruption occurred at Black Diamond Pool in Biscuit Basin, site of a hydrothermal explosion last summer.  The event was recorded by a new webcam installed earlier in May.

Recent Work and News

Very little activity has occurred at Steamboat Geyser since its most recent eruption on April 14.  This suggests it may still be at least several weeks before the geyser’s next major eruption.

On May 14, a new webcam was installed at Biscuit Basin to track activity at Black Diamond Pool, where a hydrothermal explosion occurred last summer.  The camera posts a static image every 15 minutes to https://www.usgs.gov/media/webcams/biscuit-basin-webcam, and video is logged on site for later download as needed.  Analysis of the static images indicated changes in the pool on the evening of May 31, and downloaded video captured a small eruption from the pool at 8:39 p.m. MDT.  This is the first eruption from Black Diamond Pool that has been captured on video since the hydrothermal explosion on July 23, 2024, although there is evidence from other monitoring data and some eyewitnesses that sporadic eruptions have occurred several times since the July 2024 event.

During May, Yellowstone Volcano Observatory scientists deployed semi-permanent GPS stations in the region to track surface deformation.  These stations are set up every spring to densify the continuous GPS network, and they are recovered in the fall before they are buried by snow.  Maintenance of geophysical and temperature monitoring stations was also completed, and the new webcam was established at Biscuit Basin.  Additional work that will hopefully lead to a new seismic/acoustic/GPS station at Biscuit Basin is planned for June.

Seismicity

During May 2025, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, located 119 earthquakes in the Yellowstone National Park region. The largest event of the month was a micro earthquake of magnitude 2.7 located about 7 miles north of Lake in Yellowstone National Park on May 26 at 6:39 p.m. MDT.

May seismicity in Yellowstone was marked by three swarms:

1. A swarm of 36 earthquakes, located approximately 4 miles north-northeast of West Yellowstone, MT, occurred on May 7. The largest earthquake in the sequence was a magnitude 1.8 on May 7 at 5:35 a.m. MDT.

2. A swarm of 10 earthquakes occurred about 4 miles north-northeast of West Yellowstone, MT, during May 18–19. This is the same area as the swarm described above, and the largest earthquake in the sequence was a magnitude 1.5 on May 18 at 7:46 a.m. MDT.

3. A swarm of 18 earthquakes, located approximately 5 miles northeast of West Yellowstone, MT, occurred during May 12–17. The largest earthquake in the sequence was a magnitude 2.1 on May 16 at 12:04 a.m. MDT.

Yellowstone earthquake activity remains at background levels.

Ground Deformation

Continuous GPS stations in Yellowstone Caldera recorded a small amount (about 3 centimeters, or 1.2 inches) of subsidence since October.  This pattern and rate of subsidence continues a trend that started in 2015–2016.  Minor subsidence (about 1 centimeter, or about half an inch) was also measured by a continuous GPS station near Norris Geyser Basin since the end of last summer, although no deformation has occurred at that site over the past 2 months.

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