USGS Volcano Notice - DOI-USGS-YVO-2022-11-01T09:48:00-07:00

Recent Work and News

October saw the end of major field work in Yellowstone, including maintenance on the Norris temperature-monitoring network and the recovery of several temporary GPS stations, which are deployed every May and collected in October before the onset of winter.  Field crews will continue small-scale operations until winter snows set in and make large parts of the region inaccessible.

Steamboat Geyser did not experience any major water eruptions during October, and the total number of eruptions in 2022 remains at 9.  Minor eruptions at the geyser resumed in mid-October after a few-week hiatus following the most recent major eruption on September 18, suggesting that another major eruption will occur in the next few days to weeks.

Seismicity

During October 2022, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, located 344 earthquakes in the Yellowstone National Park region. The largest event of the month was a minor earthquake of magnitude 2.9 located about 14 miles south-southwest of Mammoth Hot Springs in Yellowstone National Park on October 13 at 5:11 AM MDT.  This event is part of ongoing seismicity that began in the area on July 29.  In October, 238 earthquakes were added to the sequence, and seismicity continued through the end of the month.

October seismicity was marked by two additional swarms:

1) A swarm of 27 earthquakes, ~12 miles northeast of Old Faithful in Yellowstone National Park, occurred during October 4–5, with the largest earthquake (magnitude 2.5) taking place on October 4 at 8:14 PM MDT.

2) A small swarm of 15 earthquakes, ~6 miles north of West Yellowstone, MT, occurred during October 1–2, with the largest earthquake (magnitude 2.8) recorded on October 1 at 2:39 PM MDT.

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

Yellowstone earthquake activity is currently above background levels.

Ground Deformation

Little change in ground deformation has been recorded over the past month by continuous GPS stations in Yellowstone Caldera and near Norris Geyser Basin.  Both areas hinted at a transition from slight uplift to slight subsidence (of about 1 cm, or less than an inch) in mid-September, which is a style of deformation that occurs every summer due to changes in groundwater conditions.  The subsidence did not continue throughout October, however, and no net uplift or subsidence has been detected over the past month. The long-term rate of caldera subsidence since 2015 is 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)