YELLOWSTONE volcano suffered a total of 107 earthquakes and three Steamboat geyser eruptions in November – but could this activity be a sign of the supervolcano waking from its slumber?
Yellowstone volcano’s last major eruption was 640,000 years ago and the areas surrounding the US national park just witnessed an intense November. The US Geological Survey (USGS) tracked a total of 107 earthquakes last month, fuelling speculation of the volcano stirring from its sleep. One Twitter user wrote on December 2: “Y’all ever just remember that the Yellowstone volcano could erupt ay any moment?”
Another person said: “I very frequently think about the Yellowstone super volcano and that’s probably where my troubles started.”
In November, tracking stations operated by the University of Utah detected a total of 107 earthquakes in the Yellowstone National Park region.
The most powerful of the tremors peaked at magnitude 3.1 just 19 miles northwest of West Yellowstone, Montana.
The earthquake struck around 6.28pm local time on November 9.
The period of activity was then “capped off” by an earthquake swarm that started on November 30 and continued into December.
The earthquakes were tracked to about two miles west-northwest of West Thumb inside of Yellowstone National Park.
During the largest November swarm, the earthquakes peaked at a magnitude of 2.1.
On top of the earthquake activity, the USGS noted three eruptions of the world-famous Steamboat Geyser.
The boiling pool of water spewed scorching jets on November 8, November 17 and November 27.
In total, Steamboat geyser has erupted 45 times so far in 2019.
The USGS’ monitoring stations have also noted some ground movement in the Yellowstone area.
Since September, the Norris Geyser Basin has dropped by less than an inch.
The agency said: “Ground deformation in the Yellowstone area has been variable but minor over the last few months.
“Overall subsidence of Yellowstone caldera is indicated at stations on both the Sour Creek and Mallard Lake resurgent domes, although minor deviations are superimposed on the general trend, perhaps due to seasonal variations from inclement weather.
“In the area of Norris Geyser Basin, GPS data show subsidence of about two centimetres – less than one inch – since September, but there was little net motion during the month of November.”
Thankfully, none of these events signal any type of worrying activity deep underground.
According to the USGS, earthquake activity at Yellowstone “remains at background levels”.
Earthquake swarms also account for approximately 50 percent of all the earthquake activity in the Yellowstone region.
The USGS said: “Almost all earthquakes at Yellowstone are brittle-failure events caused when rocks break due to crustal stresses.
“Though we’ve been looking for years at Yellowstone, no one has yet identified ‘long-period (LP) events’ commonly attributed to magma movement.
“When they are observed, that will not mean Yellowstone is getting ready to erupt.”
Yellowstone’s most recent caldera-forming blast went off about 640,000 years ago.
Since then, geologists have detected about 80 “relatively nonexplosive eruptions”.
Of the 80 eruptions, at least 27 produced rhyolite lava flows from volcano’s caldera.
The most recent volcanic eruption went off about 70,000 years ago.
In total, geologists recognise three major eruptions of the Yellowstone caldera.
The eruptions are the Huckleberry Ridge eruption 2.1 million years ago, the Mesa Falls eruption 1.3 million years ago and the Lava Creek eruption 640,000 years ago.
The Lava Creek blast formed the Yellowstone Caldera and Lava Creek Tuff in Wyoming, Montana and Idaho.
In the area of Norris Geyser Basin, GPS data show subsidence of about 2cm