Researchers have officially announced that the volcanic activity in Yellowstone National Park spurred more than 1,000 earthquakes beginning in January. According to Jamie Farrell, a research assistant professor in the Department of Geology & Geophysics at the University of Utah, the earthquake swarm has periods of increased activity, before becoming more dormant.
At this time the swarm was most active from late August to mid-September. For instance, in September alone, the swarm, nearly 12 miles south-south-west of Mammoth Hot Springs, produced over 500 earthquakes.
In October, the University of Utah reported 238 earthquakes as part of this swarm, out of 344 in the entire Yellowstone area. In the U.S., the park is one of the most seismically active areas. Since 1973, more than 50,000 earthquakes have been recorded in America’s oldest national park. However, most are too small to be felt.
Over 1,000 earthquakes reported in Yellowstone in 2022 alone
The park, which stretches across Wyoming, Montana, and Idaho, is perched on an active yet relatively young and active volcanic system that many call the Yellowstone Supervolcano. This system features boiling magma, pressurized waters, and a variety of active faults.
Every year, the park averages about 1,500-2,500 earthquakes. Nearly half of them manifest as swarms. These swarms happen when seismic activity occurs in a local area over a short period without the main shock.
In 2022, the ongoing swarm created more than 1,000 events, which is still going up, according to Farrell. The phenomenon began with a small cluster at the start of the year. However, most of the quakes occurred in the latter half of the year.
However, the earthquakes have not recorded a magnitude greater than 3.9, meaning they’re considered minor. So while you might feel an earthquake like this, it would rarely do any damage.
Most of the earthquakes in the swarm are much weaker, with many being undetectable to us. They only became detectable with seismometers.
In addition, the occurrence of earthquake swarms in volcanic regions is not exclusive to the national park. According to Farrell, there are a few reasons why these swarms occur, but in volcanic areas, the most common cause is the movement of fluids in the crust.
“These fluids could be a number of different sources: magma, water, gases, among others,” he said. “The most-likely culprit is water moving through the crust but we can’t be 100 percent sure about this.”
In Yellowstone’s entirety, the University of Utah recorded over 2,100 earthquakes since New Year’s Day of this year, which falls within the annual average range. Last year, according to the United States Geological Survey’s Yellowstone Volcano Observatory annual report, 2,773 earthquakes were recorded in the area.