Last June, Yellowstone National Park was trembling a lot due to a swarm of earthquakes. According to the University of Utah Seismograph Stations (UUSS), the swarm consists of total 878 earthquakes.
Swarms are very common in Yellowstone. Jamie Farrell, a research professor at the University of Utah, told Newsweek that
“On average, Yellowstone sees around 1,500-2,000 earthquakes per year. Of those, 40 to 50 percent occur as part of earthquake swarms.”
Although there is no imminent danger, still it might be a problem if Yellowstone erupts.
In the same interview, Farrell told that
“If Yellowstone erupts, it’s most likely to be a lava flow, as occurred in nearly all the 80 eruptions since the last ‘supereruption’ 640,000 years ago,”