Thankfully they don’t happen too often, but the biggest volcanic explosions the world has seen have had devastating effects.
The past 2.1 million years has seen Yellowstone explode in three significant events – 2.1 million, 1.3 million, and 640,000 years ago – each of which blanketed the whole North American continent with debris and ash.
Each eruption caused the ground beneath the volcano to collapse, forming the huge caldera which today comprises almost a third of Yellowstone National Park’s total area. While there’s no hard evidence to suggest that a large-scale eruption of this supervolcano will occur anytime soon, the consequences could be extreme. Research suggests that a Yellowstone super-eruption could spread volcanic ash as reflective as snow across most of North America, and significantly cool the world’s climate for years.
Toba, North Sumatra, Indonesia
The explosion of this Indonesian supervolcano 75,000 years ago is regarded as one of the world’s most explosive volcanic events.
Palaeontologists thought Toba’s eruption plunged our planet into a volcanic winter, pushing our species through an evolutionary bottleneck and putting our ancestors on the brink of extinction.
Recent research suggests otherwise – that even though Toba’s tantrum did cool the climate as ash spread across most of the Indian Ocean – it didn’t cause the near-extinction of the human race.
No evidence has yet been found in the sediment record that suggests that East Africa – a hub of human settlement at the time – was affected by the volcano. So while the eruption’s timing coincided with the human bottleneck, it didn’t cause it.
Luckily, scientists don’t believe Toba will be blowing its top anytime soon; they predict the next super eruption is still dozens- if not hundreds of thousands of years away.
Campi Flegrei, Italy
While Mount Vesuvius and the tale of Pompeii are well known, Vesuvius is superseded by its unsung supervolcano neighbour, Campi Flegrei, or the Phlegrean Fields.
The Phlegrean Fields last erupted in 1538, and while it was a relatively mild eruption, it lasted a week and killed 24 people.
Historically, the caldera was born out of two distinct eruptions, occurring around 40,000 and 15,000 years ago. They spewed out up to 300 cubic kilometres of magma, with tens of kilometres around the site obliterated by pyroclastic flows.
The city of Naples is jammed between the two, with the city’s western edge literally living inside the Campi Flegrei’s caldera.
Nowadays, the area is monitored closely, as geological fluctuations in the region over the past few years have caused concern.
Rumoured to have inspired the blood-red sky of Edvard Munch’s famous painting The Scream, the effects of the 1883 almighty crack of Krakatoa in Indonesia were felt worldwide.
The eruption tore open the walls of the Krakatoa volcano and seawater rushed in. As cool water met superheated molten material, the volcano exploded with a blast heard up to 3,500 kilometres away in Australia, earning it the title of the loudest sound in recorded history.
The tsunami that ensued killed more than 35,000 people and volcanic aerosols in the atmosphere caused widespread ocean cooling.
The eruption of this Icelandic volcano in 1783 lasted eight months, spouting volcanic material that spread a haze across Europe.
As acid rain showered upon Iceland, crops were destroyed, livestock was poisoned and a quarter of Iceland’s population died in the resulting famine.
While technically a low-energy eruption, its long duration and the huge amount of material it spewed into the atmosphere meant the whole northern hemisphere dropped a full degree Celsius.
It’s even been suggested that the resulting climatic changes that occurred in Europe brought about the food shortages that spurred on the French Revolution.
Mount Tambora, Indonesia
In the most destructive explosion of the past 10,000 years, the eruption of Mount Tambora killed around 10,000 people instantly with pyroclastic flows that raced down the volcano’s side.
When these superheated rivers of lava and gas reached the sea, they set off tsunamis which devastated surrounding islands. An estimated total of 70,000 peopled died as a result of Tambora’s explosion, the biggest known death toll of any volcanic eruption.
While seismic activity has been detected within the volcano’s caldera over the past few years, geologists say that we can rest easy knowing that, while a small eruption isn’t off the table, it’s extremely unlikely we’ll see another cataclysmic eruption occurring anytime soon.
Around 1600 BC, this explosion is thought to have showered over a million cubic metres of ash onto the ancient Greek city of Thera, now known as Santorini. Located in the Mediterranean ocean, seawater flushed into the volcano’s vent and intensified the violent eruption.
The volcano – known as Kolumbo – exploded a mere seven kilometres from modern-day Santorini, and the resulting tsunami is thought to have wiped out the Minoan civilisation living on the nearby island of Crete.
Recent monitoring hints that a highly active region is developing beneath the volcano, but thankfully any future explosive eruption is predicted to be much smaller than the one that wiped out the Minoans and not a contender for making the biggest volcanic explosions list.
Related reading: The tricky science of tracking and predicting volcanic eruptions