09/02/2026
YELLOWSTONE VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Tuesday, September 1, 2026, 6:55 PM MDT (Wednesday, September 2, 2026, 00:55 UTC)
YELLOWSTONE VOLCANO (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
Yellowstone Caldera activity remains at background levels, with 61 located earthquakes in August (largest = M2.0). Deformation measurements indicate no significant uplift of the north caldera rim since January 2026 and only minor uplift of the caldera since the beginning of the year.
Recent Work and News
August field work included studies of hydrothermal explosion craters and glacial geology, as well as continued upgrades to the Yellowstone Seismic Network. In September, YVO hopes to bring a new seismic and infrasound station fully online in Upper Geyser Basin. The station is designed to record hydrothermal activity in the region, especially in the vicinity of Geyser Hill.
Black Diamond Pool, in Biscuit Basin, had a few small eruptions in early to mid August. Monitoring data suggest there was also one large eruption that probably threw water and mud tens of feet (many meters) into the air, but it occurred at about 10 PM on August 13, and no visual observations from nearby cameras were possible. Water temperature data indicate no clear eruptions and only two overflow events on August 22 at Echinus Geyser, in Norris Geyser Basin, and nearby Steamboat Geyser had only minor eruptive activity during the month. Giant Geyser, in Upper Geyser Basin, erupted on August 17 and 30—its second and third eruptions of the year.
Seismicity
During August 2026, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, located 61 earthquakes in the Yellowstone National Park region. The largest event of the month was a micro earthquake of magnitude 2.0 located about 22 miles east-northeast of Canyon Village in Yellowstone National Park on August 5 at 4:05 p.m. MDT.
There were no swarms identified during August.
Earthquake activity in Yellowstone is at background levels.
Ground Deformation
Data from continuous GPS stations indicate that the uplift that started in July 2025 on the north caldera rim ceased by mid-January 2026 and has not resumed. Subtle uplift of the caldera itself amounted to about 1 cm or less (a fraction of an inch) over the course of the past few months, possibly due to seasonal variations associated with groundwater 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)
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
UNAVCO, a non-profit university-governed consortium, facilitates geoscience research and education using geodesy.
