Scientists Detect 200 Earthquakes in 10 Days at Yellowstone Supervolcano as Magma Shows ‘Strain’.
Given the Earth-shattering power of this super volcano — which is capable of covering much of the United States under a thick blanket of lava and ash — it’s enough to raise some serious eyebrows.
But none of the quakes have been huge: the biggest came in at just magnitude 2.9.
This means the shake was just strong enough to be barely felt by some people. But there was no damage to any structures.
And the underground movements that caused them are not likely to have had any impact on the 250 billion cubic kilometre ticking time bomb of molten rock.
That we know of.
The United States Geological Service says most of the flurry of activity came at a depth of about 8km, near West Yellowstone, Montana.
Earthquake swarms are nothing new.
Especially in Yellowstone.
They can be triggered by a shift in pressure along a fault line.
This can be caused by changes in the amount of nearby subterranean water or gas. As well as movements of magma.
Yellowstone has an excess of all three.
Movements in the massive tectonic plates that shape our planet’s surface can also play a part.
One of these is also at play under Yellowstone.
The US National Parks Service says that, on average, Yellowstone is generally shaken by between 1000 and 3000 quakes every year.
“It is not an imminent hazard,” volcanologist Guillaume Girard told National Geographic. “Every study has concluded that there is no magma that is ready to erupt within any foreseeable future.”
But last year, 2400 earthquakes registered on seismic sensors between June and September alone.
“This is what Yellowstone does; this is Yellowstone being Yellowstone,” scientist-in-charge of the USGS Yellowstone Volcano Observatory Michael Poland told Live Science. “It experiences swarms all the time.”
The biggest quake last year was magnitude 4.4: a strength people would feel, but not likely to cause anything more than minor damage.
So far, the biggest recorded quake in the supervolcano was a magnitude 7.3 in 1959. Dozens of people died in landslides. At this level, most buildings within the affected area were seriously damaged, or collapsed.
“One of the potential explanations for why this area is so swarmy is that the whole crust in the area is still adjusting to the big earthquake in 1959,” Poland says.