Yellowstone supervolcano: Videos show animals 'fleeing' but we've nothing to fear

Videos of lines of bison and other animals ‘fleeing’ Yellowstone National Park in the US have raised fears that the supervolcano that lies underneath the park is preparing to erupt, but how much truth –if any – is there to this claim?

The clip in question was a clip uploaded to YouTube with the title “ALERT! Yellowstone Buffalo Running for Their Lives!” that quickly circulated around online blogs with one commentator, a survivalist named Tom Lupshu, offering a typical assessment that the animals had detected “something vast and deadly.”
“The Yellowstone supervolcano is the only thing there that would fit the bill,” says Lupshu.
But is the supervolcano really that scary? Well, in theory, yes. After asteroid strikes, supervolcanoes are the "second most globally cataclysmic event" that can affect the Earth, and in the past have been responsible for mass extinctions and 'volcanic winters' that last for year.
The Yellowstone supervolcano is an active hotspot, it has a massive magma chamber (scientists estimated last December that it was 2.5 times bigger than previously thought) and given what we know about its history, it erupts on a roughly 700,000 year cycle – with the last major eruption occurring some 640,000 years ago.
A cataclysmic eruption 2.1 million years ago is thought to have killed off thousands of prehistoric animals and covered nearly half of North America with ash and dust. In a nut-shell, the fear is that Yellowstone is overdue - and that the bison are the first to figure it out.

In pictures: Supervolcano in Yellowstone National Park

However, Yellowstone Park authorities have stepped into the breach to clear up the muddle, with Public Affairs chief Al Nash calmlypointing out that the video of the bison 'fleeing' actually shows normal migration patterns of animals in the park.
“We do have bison, elk and other animals that have moved outside the park recently,” explains Nash in a video on YouTube, “but they’re doing that because it’s the depth of winter. Food is a little hard to find places in side Yellowstone and they tend to migrate at this time of the winter outside of the park to lower elevations where they think there might be something to eat that’s easier to get at.”
“When the snow melts off and things start to green those very same animals will walk straight back into the park,” says Nash, who also points out that although the park has been hit by some large earthquakes in recent weeks, none of these are beyond the bounds of normal seismic activity.
So although supervolcanos are a pretty scary concept there's absolutely no indication that the one in Yellowstone is any nearer to erupting than previously thought. There's some comfort in that.