Hazard Notification System (HANS) for Volcanoes


U.S. Geological Survey
Thursday, September 1, 2022, 12:33 PM MDT (Thursday, September 1, 2022, 18:33 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

Yellowstone Volcano Observatory scientists have a busy month of work planned for September.  In addition to the typical late summer maintenance of the seismic and deformation monitoring networks, new gas monitoring equipment will be installed at the existing Multi-GAS continuous site in the Mud Volcano area.  A number of YVO and academic scientists will also visit the new thermal area near Tern Lake to collect gas samples and study tree-growth patterns to better understand the development of hydrothermal activity at the site.  Finally, a temporary deployment of geophysical sensors throughout the park is planned to map subsurface geological conditions and fluid pathways.

Steamboat Geyser did not erupt during the month of August (the most recent eruption occurred on June 20).  There have been 8 major water eruptions of the geyser in 2022.


During August 2022, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, located 290 earthquakes in the Yellowstone National Park region. The largest event of the month was a minor earthquake of magnitude 3.1 located about 15 miles south-southwest of Mammoth Hot Springs in Yellowstone National Park on August 25 at 11:51 PM MDT.  This event is part of ongoing seismicity that began July 29—221 of the August earthquakes occurred as part of this swarm, and seismicity continued into September.

Earthquake sequences like these are common and account for roughly 50% of the total seismicity in the Yellowstone region.

An earthquake of magnitude 3.3 occurred on the local night of August 31 near Lewis Lake, in the south part of Yellowstone National Park. Because this event occurred on September 1 in the UTC time zone (which is used by seismologists to define the month boundaries), it will be covered in next month’s update.

Yellowstone earthquake activity remains at background levels.

Ground Deformation

Continuous GPS stations in Yellowstone Caldera and near Norris Geyser Basin recorded about a centimeter of uplift (about half an inch) since the start of summer.  This deformation is a result of snowmelt that percolates into the ground and causes the surface to swell slightly, like a sponge.  The same summer-only signal is detected annually and is superimposed on the overall trend of caldera subsidence, which has been ongoing since 2015 at a rate of a few centimeters (1–2 inches) per year.

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