Skip to content. | Skip to navigation

Yellowstone supervolcano

Yellowstone supervolcanoLearn about the sleeping dragon that lies beneath Yellowstone Park. When will it erupt, and what will happen to the human race when it does?

Yellowstone Park in America is an area of outstanding natural beauty. Three million people visit the Park annually to see the thousands of spewing geysers, hissing steam vents, gurgling mud pots and boiling hot springs that help make Yellowstone such an otherworldly attraction. However, few people are aware that these fascinating features are due to the existence of one of the largest supervolcanoes in the world.


Only a handful of supervolcanoes exist in the world but when one erupts it will be unlike any volcano we have ever witnessed. The explosion will be heard around the world. The sky will darken, black rain will fall, and the Earth will be plunged into the equivalent of a nuclear winter.

Scientists have shown that the caldera (the ‘bowl’ of the volcano) is 40 miles across and that the supervolcano has been on a regular eruption cycle of 600,000 years. The last eruption was 640,000 years ago... so the next is long overdue. Even more disturbing news - the sleeping giant is breathing: volcanologists have been tracking the movement of magma under the park and have calculated that in parts of Yellowstone the ground has risen over 70 centimetres in the 20th century. Since 2004 the ground above the caldera has moved upwards at a rate of up to seven centimetres a year—more than three times faster than has ever been measured. Is this just the harmless movement of lava, flowing from one part of the reservoir to another? Or does it presage something much more sinister, a pressurised build-up of molten lava?

Scientists have very few answers, but they do know that the impact of a Yellowstone eruption would be cataclysmic. Huge areas of the USA would be destroyed, the US economy would probably collapse, and thousands might die. And it could devastate the planet. It would blast so much ash and sulphur dioxide into the stratosphere that it would block out the sun, causing the Earth's temperature to plummet. Some geneticists now believe that it could have a catastrophic effect on human life, possibly reducing the population on Earth to just a few thousand people.

Fun facts!

  • In 2005 the BBC rescheduled their docudrama ‘Supervolcano’, about the potential Yellowstone eruption. It was thought that the subject was too sensitive to deal with just after the Indian Ocean Tsunami of 2004.
  • The largest known supervolcanic eruption in Earth’s history happened in Colorado in the US, over 27 million years ago.
  • Volcanic lava flows are rarely deadly as they generally move slower than walking pace. It is the gases and debris thrown out by the volcano that lead to casualties and a high death toll.

Related links