Modern humans have never experienced the wrath of a supervolcano eruption—and if they had, humanity’s survival might not have been guaranteed.
These cataclysmic events, which dwarf typical volcanic eruptions, have the potential to alter the course of the planet, reshape ecosystems, and cause widespread devastation.
Unlike regular volcanoes, supervolcanoes unleash eruptions that register at magnitude eight on the Volcano Explosivity Index (VEI), releasing over 1,000 cubic kilometres (240 cubic miles) of volcanic material in a single event.
For context, the infamous eruption of Krakatoa, Indonesia, in 1883, which caused a devastating tsunami and claimed over 36,000 lives, pales compared to what a supervolcano could unleash.
While Krakatoa remains one of history’s most catastrophic eruptions, it doesn’t qualify as a supervolcano. Instead, scientists have long monitored volcanic giants like Yellowstone, nestled in the US state of Wyoming, with concern.
Volcanic activity at Yellowstone began approximately two million years ago, producing three massive eruptions throughout its geologic history. These eruptions—occurring 2.1 million, 1.3 million, and 630,000 years ago—were unlike anything modern science has observed, ejecting enough ash and debris to bury entire regions and influencing global climates for decades.
The most recent eruption, 630,000 years ago, was estimated to be 1,000 times more powerful than the 1980 Mount St. Helens eruption, which caused over $1 billion (£800 million) in damage. Yellowstone’s explosive potential is rooted in its massive magma reservoir, which lies beneath the surface of Yellowstone National Park, a region famous for its geysers, hot springs, and stunning landscapes.
According to the United States Geological Survey (USGS), Yellowstone has been relatively stable for the past 140 years. However, experts continue to study its behaviour, knowing the potential consequences of its awakening.
If Yellowstone were to erupt tomorrow, the consequences would be devastating. The Smithsonian Channel’s short documentary, What If the Yellowstone Volcano Erupted Tomorrow? Explores this hypothetical scenario, painting a grim picture of the aftermath.
Talking about the wildly unpredictable situation, the narrator noted: “Right now, in the US, one of the world’s largest volcanoes is gearing up to explode. If Yellowstone decided to erupt, the results would be devastating.
“It has erupted three times in the past three million years, which has led some people to wonder whether we should be worried about another eruption in the near future. But if the eruption took place tomorrow and you lived in North America, there would be virtually nothing you could do to prepare.”
Dr Robert B. Smith, a renowned geophysicist and expert on supervolcanoes, describes the potential devastation as “complete and incomprehensible.” Unlike smaller volcanic eruptions that primarily produce lava flows, a Yellowstone eruption would eject most of its magma as ash, creating colossal plumes that would blanket much of North America and spread across the globe.
Within a 1,000-kilometre (621-mile) radius, tens of millions of people could perish from suffocation, as inhaling volcanic ash forms a cement-like substance in the lungs. Structures wouldn’t fare much better—just 30 centimetres (12 inches) of ash is enough to collapse most roofs.
Farther away, even regions thousands of kilometres from the eruption would face dire consequences. A centimetre of ash could contaminate water supplies, destroy crops, and cripple infrastructure. Globally, temperatures could drop by as much as 10°C, triggering a “volcanic winter” that could last up to a decade. Such a climate shift would devastate agriculture and create food shortages, leading to widespread famine and migration.
Fortunately, the odds of a supervolcano eruption occurring in our lifetimes are exceedingly low. The USGS emphasizes that Yellowstone’s current activity—including minor earthquakes and geothermal features—is consistent with its behaviour over the past 140 years. “Odds are very high that Yellowstone will remain eruption-free for centuries to come,” the agency states.
However, this hasn’t stopped scientists from studying the potential risks. Professor Christopher Kilburn, a volcanologist at University College London, previously warned that many of the world’s supervolcanoes are not being adequately monitored. He highlighted the potential for immense agricultural disruption in the central United States, previously telling Express.co.uk: “The wheat belt and other agricultural producing areas would just be wiped out. It would result in unimaginable migration and geopolitical challenges.”
Supervolcano eruptions are rare, with the last known event occurring roughly 26,500 years ago in New Zealand. However, their impact on the planet is undeniable. Beyond immediate destruction, supervolcanoes can trigger long-term environmental changes, influencing everything from atmospheric composition to ocean temperatures.
For now, Yellowstone’s beauty and geothermal wonders draw millions of visitors annually, a far cry from the apocalyptic scenario scientists imagine in the event of an eruption. However, as researchers continue to uncover more about supervolcanoes’ past and potential future, their work underscores the importance of preparedness and understanding the power of the Earth beneath the surface.
