Monthly update of activity at Yellowstone Volcano (April 1, 2022)
Yellowstone Volcano Observatory Scientist-in-Charge Mike Poland talks about a recent earthquake swarm in Yellowstone National Park, trends in ground deformation, and water eruptions at Steamboat Geyser, in this video update of recent activity (April 1, 2022).
Seismic swarms are nothing new in Yellowstone. In fact, about 50% of all earthquakes in Yellowstone are part of swarms. The recent swarm that began on March 28, 2022 occurred in an area where earthquakes are common. There are at least three reasons why this area is so active: (1) Yellowstone sits right on the eastern edge of the Basin and Range extensional province so there are many faults in the area; (2) a lot of snow and rain moves into the subsurface to interact with those faults, generating small earthquakes; and (3) the 1959 Hebgen Lake earthquake (the largest earthquake ever recorded in the Intermountain West Region of the U.S.) altered the stress field in the rock to make small earthquakes more likely. That is why earthquakes are so common in this particular area and why they don’t really have anything to do with volcanic activity or magmatic activity. Yellowstone earthquake activity remains at background levels.
No significant changes in ground deformation patterns were observed in data from continuous GPS stations over the past several months. The Yellowstone Caldera continues to subside at an overall rate of 2–3 cm (1 in) per year. This subsidence has been ongoing since 2015.
Steamboat Geyser continues to be active in 2022, although the frequency of its eruptions has decreased dramatically compared to the preceding three years. The geyser experienced two major water eruptions in the past month, on March 4 and March 30.