Yellowstone volcano earthquake monitoring stations have recorded 81 tremors within the national park area. Seismic activity in February 2019 included a terrifying swarm of earthquakes, which struck just north of West Yellowstone in Montana. The earthquake swarm saw up to 17 tremors of varying strength hit the national park in Northwest US. According to a USGS report, the strongest of the swarm tremors peaked at a strength of magnitude 1.7 on February 20.
A much stronger event was recorded on February 16, when a magnitude 3.1 tremor was felt 16 miles (25.7km) south of West Yellowstone.
The USGS said: “During February 2019, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, located 81 earthquakes in the Yellowstone National Park region.
“The largest event was a minor earthquake of magnitude 3.1 located 14 miles south of West Yellowstone, MT, on February 16 at 2.22pm MST.
“The earthquake was reported felt in Yellowstone National Park.
“February seismicity in Yellowstone included a swarm of 17 located earthquakes on February 20.
“The swarm events ranged in magnitude from 0.1 to 1.7 and were located five miles north of West Yellowstone, MT.”
However, overall seismic activity at the Yellowstone supervolcano remains at “background levels”.
The USGS also assured earthquake swarms are a typical occurrence in the region.
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At least 50 percent of all earthquakes in Yellowstone strike in the form of swarms.
Despite the frequent earthquakes, authorities have not noticed any significant changes in ground deformation throughout the park.
GPS stations have recorded ongoing subsidence of the Yellowstone volcano caldera, but the movement matches rates established in 2015.
The USGS said the supervolcano’s caldera is slowly dropping at a rate of “a few millimetres per month”.
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In the month of February, there were also four eruptions of the world-famous Steamboat Geyser.
The USGS recorded scorching blasts of water on February 1, 8, 16 and 26 – roughly one week apart each.
The geological agency said: Discharge measured at the Tantalus stream gage suggests that these eruptions may have been smaller than past events of the current sequence, which started in March 2018, although it is difficult to confirm this without direct observations.”
With the limited signs of volcanic activity at background levels, the current warning else for Yellowstone is “Normal”, meaning the supervolcano is behaving in a non-eruptive manner.
