James Stewart

Because of this threat, and because of the region's long history of activity, scientists continually observed the Yellowstone volcano for signs of ground deformation, earthquakes and volcanic gases, which could indicate magma on the move. The problem is the Yellowstone region is so active that such occurrences are almost constant.

Because of this threat, and because of the region's long history of activity, scientists continually observed the Yellowstone volcano for signs of ground deformation, earthquakes and volcanic gases, which could indicate magma on the move. The problem is the Yellowstone region is so active that such occurrences are almost constant.

And because nobody has ever actually witnessed the buildup to a super volcanic eruption, we can't be absolutely sure what we should expect to see before it blows. Based on the average times between the last few eruptions of the Yellowstone volcano, the chance of an eruption occurring there in any given year has been estimated at one in 730,000. But that's not really how volcanoes work.

And because nobody has ever actually witnessed the buildup to a super volcanic eruption, we can't be absolutely sure what we should expect to see before it blows. Based on the average times between the last few eruptions of the Yellowstone volcano, the chance of an eruption occurring there in any given year has been estimated at one in 730,000. But that's not really how volcanoes work.

And because nobody has ever actually witnessed the buildup to a super volcanic eruption, we can't be absolutely sure what we should expect to see before it blows. Based on the average times between the last few eruptions of the Yellowstone volcano, the chance of an eruption occurring there in any given year has been estimated at one in 730,000. But that's not really how volcanoes work.

They don't hold to schedules like that, so it would be inaccurate to say whether an eruption is due or not. Still, geologists monitoring the Yellowstone supervolcano are confident that there are currently no signs that magma is accumulating in a large enough quantity to feed such an eruption at any time soon.

They don't hold to schedules like that, so it would be inaccurate to say whether an eruption is due or not. Still, geologists monitoring the Yellowstone supervolcano are confident that there are currently no signs that magma is accumulating in a large enough quantity to feed such an eruption at any time soon.

They don't hold to schedules like that, so it would be inaccurate to say whether an eruption is due or not. Still, geologists monitoring the Yellowstone supervolcano are confident that there are currently no signs that magma is accumulating in a large enough quantity to feed such an eruption at any time soon.

But there are many more sites where huge eruptions have created large calderas, and where a VEI-8 event could plausibly occur. And even if an eruption doesn't quite reach the magnitude necessary to qualify for the top category, it could still be locally catastrophic. One such site is the Flagrian Fields near Naples in Italy.

But there are many more sites where huge eruptions have created large calderas, and where a VEI-8 event could plausibly occur. And even if an eruption doesn't quite reach the magnitude necessary to qualify for the top category, it could still be locally catastrophic. One such site is the Flagrian Fields near Naples in Italy.

But there are many more sites where huge eruptions have created large calderas, and where a VEI-8 event could plausibly occur. And even if an eruption doesn't quite reach the magnitude necessary to qualify for the top category, it could still be locally catastrophic. One such site is the Flagrian Fields near Naples in Italy.

This large complex of calderas lies just across the Gulf of Naples from Mount Vesuvius, the volcano that famously buried the Roman town of Pompeii in 79 AD. While that event might seem bad enough, it scored 5 on the VEI scale incidentally, an eruption of the Phalagrian fields could be hundreds of times larger.

This large complex of calderas lies just across the Gulf of Naples from Mount Vesuvius, the volcano that famously buried the Roman town of Pompeii in 79 AD. While that event might seem bad enough, it scored 5 on the VEI scale incidentally, an eruption of the Phalagrian fields could be hundreds of times larger.

This large complex of calderas lies just across the Gulf of Naples from Mount Vesuvius, the volcano that famously buried the Roman town of Pompeii in 79 AD. While that event might seem bad enough, it scored 5 on the VEI scale incidentally, an eruption of the Phalagrian fields could be hundreds of times larger.

It has been suggested that the climate effect of an eruption about 39,000 years ago helped to see off the Neanderthals, who disappeared from Europe around this time. Although, like the Toba Catastrophe Hypothesis, this claim is disputed.

It has been suggested that the climate effect of an eruption about 39,000 years ago helped to see off the Neanderthals, who disappeared from Europe around this time. Although, like the Toba Catastrophe Hypothesis, this claim is disputed.

It has been suggested that the climate effect of an eruption about 39,000 years ago helped to see off the Neanderthals, who disappeared from Europe around this time. Although, like the Toba Catastrophe Hypothesis, this claim is disputed.

In the last few years, activity at the Flagrian Fields seems to be intensifying, with increasing earthquakes and ground deformation causing alarm among volcanologists. Although the probability of a large eruption is still considered very low, the situation is serious enough for authorities to devise an evacuation plan for more than a million residents of the area.

In the last few years, activity at the Flagrian Fields seems to be intensifying, with increasing earthquakes and ground deformation causing alarm among volcanologists. Although the probability of a large eruption is still considered very low, the situation is serious enough for authorities to devise an evacuation plan for more than a million residents of the area.

In the last few years, activity at the Flagrian Fields seems to be intensifying, with increasing earthquakes and ground deformation causing alarm among volcanologists. Although the probability of a large eruption is still considered very low, the situation is serious enough for authorities to devise an evacuation plan for more than a million residents of the area.