Hazard Notification System (HANS) for Volcanoes
Home | VONAs | Volcano Notice Search | Resources
Newest Volcano Notice Including Yellowstone
YELLOWSTONE VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Monday, June 1, 2026, 10:55 AM MDT (Monday, June 1, 2026, 16:55 UTC)
YELLOWSTONE (VNUM #325010)
44°25'48" N 110°40'12" W, Summit Elevation 9203 ft (2805 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
Summary: YVO Monthly Update: background seismicity and deformation
Summary
Yellowstone Caldera activity remains at background levels, with 45 located earthquakes in May (largest = M2.0). Deformation measurements indicate no significant uplift or subsidence of the caldera or north caldera rim since January 2026.
Recent Work and News
Echinus Geyser, in Norris Geyser Basin, remained active, with 2 eruptions in May. The month also included eruptions of Black Diamond Pool in Biscuit Basin (site of a hydrothermal explosion in 2024) that were recorded by acoustic, seismic, and temperature measurements on May 5 and 11. The biennial coordination meeting of the Yellowstone Volcano Observatory took place during May 18-20 at Mammoth Hot Springs, with discussions focusing on how to update geologic maps of the park and better anticipate and detect hazardous hydrothermal events. Field work included the seasonal deployment of semipermanent GPS stations, which are temporary GPS sites that are set up every May and recovered in September/October and serve to densify the ground deformation monitoring network during summer months.
Seismicity
During May 2026, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, located 45 earthquakes in the Yellowstone National Park region. The largest event of the month was a microearthquake of magnitude 2.0 located about 20 miles south-southeast of Mammoth Hot Springs in Yellowstone National Park on May 21 at 11:08 p.m. MDT.
There were no swarms identified during May.
Earthquake activity in Yellowstone is at background levels.
Ground Deformation
Data from continuous GPS stations indicate little net deformation in the region since January 2026. The uplift that started in July 2025 on the north caldera rim ceased by mid-January 2026, and there has been no uplift or subsidence of Yellowstone Caldera since December 2025.
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, Earthscope Consortium, Wyoming State Geological Survey, Montana Bureau of Mines and Geology, Idaho Geological Survey
CONTACT INFORMATION:
Michael Poland, Scientist-in-Charge
mpoland@usgs.gov