Volcano Updates

Alert Level: NORMAL, Color Code: GREEN 2021-05-01 15:11:25

U.S. Geological Survey
Saturday, May 1, 2021, 9:11 AM MDT (Saturday, May 1, 2021, 15:11 UTC)

44°25'48" N 110°40'12" W, Summit Elevation 9203 ft (2805 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

Recent work and news

In the past month there were three major water eruptions of Steamboat Geyser, on April 4, 16, and 23. This brings the total number of eruptions for the year to 10.

May marks the start of the field season in Yellowstone, and geologists, geophysicists, and geochemists will begin a variety of field projects in the park this month. Some of the first work will include maintenance of GPS, seismic, and temperature monitoring stations. In addition, starting on May 10 geophysicists will install temporary GPS stations across the Yellowstone region. These stations, which will be recovered in October before the onset of winter, provide a seasonal densification of the Yellowstone ground deformation monitoring network and have been deployed annually for the past 15 years.


During April 2021, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, located 43 earthquakes in the Yellowstone National Park region. The largest event was a minor earthquake of magnitude 2.5 located 15 miles northeast of West Yellowstone, MT, on April 27 at 3:07 AM MDT.

No swarm activity was observed in April.

Yellowstone earthquake activity remains at background levels.

Ground deformation

Deformation rates and styles at Yellowstone, as recorded by continuous GPS stations, have been steady over the past year. Subsidence of Yellowstone Caldera, which has been ongoing since 2015, continued at an average rate of 2-3 cm (about 1 in) per year. In the area of Norris Geyser Basin, no significant uplift or subsidence has been detected by a nearby GPS station since the start of 2020.

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

The Yellowstone Volcano Observatory (YVO) provides long-term monitoring of volcanic and earthquake activity in the Yellowstone National Park region. Yellowstone is the site of the largest and most diverse collection of natural thermal features in the world and the first National Park. YVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.

YVO Member agencies: USGS, Yellowstone National Park, University of Utah, University of Wyoming, Montana State University, UNAVCO, Inc., Wyoming State Geological Survey, Montana Bureau of Mines and Geology, Idaho Geological Survey


Michael Poland, Scientist-in-Charge