This story first appeared on Cowboy State Daily
By Ellen Fike, Cowboy State Daily
Yellowstone National Park’s seismic activity increased in 2020, with the park experiencing about 500 more earthquakes than in 2019.
At least 1,722 earthquakes were recorded in the park in 2020, according to the Yellowstone Volcano Observatory’s annual report. This was an increase from 2019, when the park experienced 1,218 earthquakes.
However, the increase is not any cause for alarm, the report said. The park can experience anywhere from 1,500 to 2,500 earthquakes per year, according to historical records.
Only three of the 1,722 earthquakes recorded in 2020 could actually be felt, meaning people reported some shaking.
Each of the larger earthquakes were 3.1 magnitude and occurred on March 31, May 29 and Nov. 25 in the area between Hebgen Lake in Montana and Norris Geyser Basin in the park, a place that has historically experienced higher magnitude quakes.
Around 890 of the earthquakes occurred as a part of 26 “swarms,” the occurrence of a number of small earthquakes in a small area over a relatively short period. Swarms are common in Yellowstone and usually around 50% of the quakes in the park are a part of a swarm.
The largest swarm occurred the week of Sept. 10, when 123 earthquakes happened in a one-week period.
Earthquakes have been recorded in the park since the 1970s, but most are too small in magnitude to be felt by humans. The Yellowstone region is one of the most seismically active areas in the United States.
Since 1973, more than 50,000 earthquakes have been located in the park, but more than 99% of the quakes are less than a magnitude of 2.