The Yellowstone caldera is a supervolcano which spans beneath the US states of Wyoming, Montana and Idaho, and gets its chilling nickname due to its ability to inflict devastation on a global scale if it erupts. It is constantly monitored by the United States Geological Survey (USGS) for signs that a supereruption is on its way, something that has only happened three times in history, 2.1 million years ago, 1.3 million years ago and 640,000 years ago. In a video on YouTube last week, Scientist-in-Charge of the Yellowstone Volcano Observatory – Mike Poland – gave an update on activity during March.
He said: “The University of Utah seismograph stations, which is responsible for the operation and the maintenance of the Yellowstone seismic network, recorded 111 earthquakes in the Yellowstone region during the month of March 2020.
“The largest event of the month was a magnitude 3.1 on March 31, just to the west of the park boundary on the east side of Hebgen Lake.
“There were also two swarms in Yellowstone during the month, the first was a small swarm of 15 earthquakes that occurred between March 5 and March 14.
“The largest event of this swarm was a magnitude 1.7 and another swarm of 19 events, the largest being a magnitude 2.1, that occurred between March 21 and 29.
Mike Poland posted a video on the volcano
Steamboat burst back to life in March 2018
“This sort of swarm seismicity and the overall number of earthquakes in the region is pretty normal.”
Dr Poland went on to provide details on each part of the park, starting on the east side of Yellowstone.
He added: “Turning now to deformation, this is a plot of GPS vertical component of motion at the White Lake GPS station, which is located on the Sour Creek resurgent on the east side of the caldera.
“Each data point gives one day of data and the plot spans two years.
“This downward trend is showing subsidence of this site over that period, by about a few centimetres a year.
“There are some little fluctuations in that, but the overall trend is subsidence.”
READ MORE: Yellowstone volcano: USGS records 111 earthquakes across park – is the volcano awakening?
Dr Poland then discussed what the USGS had recorded on the north side of the park.
He added: “Over the other side of the caldera, near Old Faithful, we see the same overall trend over the last two years at the rate of a couple of centimetres a year.
“This has been ongoing since 2015, so caldera subsidence is continuing.
“Moving to the Norris area, just north of the caldera, that had actually been uplifting between 2015 and 2018 and you can see the tail-end of that through mid-2018.
“But by late 2018, things stopped and calmed down through to much of 2019.
“There hasn’t been a whole lot of up or down motion since the beginning of 2020.”
But Dr Poland revealed most of the activity had occurred at Steamboat Geyser.
He continued: “Let’s take a look at Steamboat – everyone’s favourite geyser.
“Steamboat had three water eruptions during the month of March – this is the temperature record of the outflow channel.
“That spike right there is an eruption that occurred on March 6, there’s another right here on March 15 and finally the last of the month on March 24.
“You can see these variations are normal air temperature variations, and then you see an increasing level of minor activity prior to each major eruption.
“We will be starting another cycle soon and would expect to see another major eruption at Steamboat by following the pattern that has been established over the last couple of years now.
“Remember Steamboat burst back to life in March 2018.”
In 2018, Steamboat Geyser entered a much more active period with 80 eruptions recorded between March 15, 2018, and December 26, 2019.
In 2018 there were 32 eruptions and 48 occurred 2019, breaking 1964’s record of 29 eruptions in a year twice.
However, the USGS says there is no reason to fear and released a statement last year.
It read: “Steamboat Geyser, in the Norris Geyser Basin, appears to have entered a phase of more frequent water eruptions, much like it did in the Sixties and early Eighties.
“Although these eruptions do not have any implications for future volcanic activity at Yellowstone, they are nonetheless spectacular, and many people had a chance to see Steamboat in eruption during the summer of 2018 and now in the summer of 2019 as well.”