Visitors to Yellowstone National Park in the north-western United States know not to be careless about the bears that roam its pines or the many hissing and sizzling geysers that dot its magnificent landscape. Few ever worry about being blown into space, though.

Startling new geological data published in the journal Science suggests that it might be a good idea for most of us – and certainly those living in the region – to be aware that there is more to Yellowstone than grand vistas and abundant wildlife. The hot springs are a clue to what lies beneath: seething layers of molten magma, super-heated gases and hydrothermal liquids.

“Our best evidence is that the crustal magma chamber is filling with molten rock,” Professor Smith explained. “But we have no idea how long this process goes on before there either is an eruption or the inflow of molten rock stops and the caldera deflates again.” In other words, something is afoot, but no techniques exist to forecast what comes next. The prediction is easier for single-channel, cone volcanoes. At a caldera such as Yellowstone, the magma could suddenly blow through at any number of locations. “We use the term ‘restless’ to describe these systems.”

And what if the ground at Yellowstone does not start to go down? Well, these calderas, he admits, “occasionally they burp”. Let’s hope the park’s belly-ache resolves itself – such a “burp” would shake half of the planet.

That’s OK. Since the studies come from scientists, half of America won’t even glance up from watching “reality” TV.