James Stewart

At a VEI of 4, you reach the 2010 eruption of the Icelandic volcano whose ash clouds spread over Europe and the Atlantic Ocean, disrupting air travel for several weeks. Because many of an eruption's attributes can't be determined with certainty, there's sometimes disagreement about what score should be assigned to a given eruption.

The 2022 Tonga event, with an erupted rock volume of about 1.9 cubic kilometres and a plume that reached a height of 58 kilometres, earns a five on the VEI scale by most estimates, although some volcanologists push it up to a six. This is roughly on a par with the famous 1980 eruption of Mount St. Helens in Washington State in the US.

The 2022 Tonga event, with an erupted rock volume of about 1.9 cubic kilometres and a plume that reached a height of 58 kilometres, earns a five on the VEI scale by most estimates, although some volcanologists push it up to a six. This is roughly on a par with the famous 1980 eruption of Mount St. Helens in Washington State in the US.

The 2022 Tonga event, with an erupted rock volume of about 1.9 cubic kilometres and a plume that reached a height of 58 kilometres, earns a five on the VEI scale by most estimates, although some volcanologists push it up to a six. This is roughly on a par with the famous 1980 eruption of Mount St. Helens in Washington State in the US.

And in case you're wondering what 1.9 cubic metres looks like, it's roughly the volume of a large open-pit mine, such as the Myrrh Diamond Mine in Russia, or the Bingham Canyon Copper Mine in the US.

And in case you're wondering what 1.9 cubic metres looks like, it's roughly the volume of a large open-pit mine, such as the Myrrh Diamond Mine in Russia, or the Bingham Canyon Copper Mine in the US.

And in case you're wondering what 1.9 cubic metres looks like, it's roughly the volume of a large open-pit mine, such as the Myrrh Diamond Mine in Russia, or the Bingham Canyon Copper Mine in the US.

Even more violent eruptions than Tonga, those firmly within category 6, include the 1991 eruption of Mount Pinatubo in the Philippines, which caused a small but measurable cooling of the globe due to the aerosols it injected into the stratosphere.

Even more violent eruptions than Tonga, those firmly within category 6, include the 1991 eruption of Mount Pinatubo in the Philippines, which caused a small but measurable cooling of the globe due to the aerosols it injected into the stratosphere.

Even more violent eruptions than Tonga, those firmly within category 6, include the 1991 eruption of Mount Pinatubo in the Philippines, which caused a small but measurable cooling of the globe due to the aerosols it injected into the stratosphere.

And the 1883 eruption of Krakatawa in Indonesia, whose ash might have been responsible for the lurid red sky depicted by Edvard Munch in his painting The Scream. A VEI of 7 is reserved for the greatest eruptions in recorded history. These come with the accompanying descriptor super colossal compared to the merely cataclysmic eruptions like Tonga in the VEI 5 bracket.

And the 1883 eruption of Krakatawa in Indonesia, whose ash might have been responsible for the lurid red sky depicted by Edvard Munch in his painting The Scream. A VEI of 7 is reserved for the greatest eruptions in recorded history. These come with the accompanying descriptor super colossal compared to the merely cataclysmic eruptions like Tonga in the VEI 5 bracket.

And the 1883 eruption of Krakatawa in Indonesia, whose ash might have been responsible for the lurid red sky depicted by Edvard Munch in his painting The Scream. A VEI of 7 is reserved for the greatest eruptions in recorded history. These come with the accompanying descriptor super colossal compared to the merely cataclysmic eruptions like Tonga in the VEI 5 bracket.

The most recent eruption rating 7 on the VEI scale was the 1815 eruption of Tambora in Indonesia, which caused tens of thousands of deaths locally and tens of thousands more worldwide due to the volcano's effects on the climate. Because of the ash that Tambora injected into the atmosphere the following year, 1816, is known as the year without a summer.

The most recent eruption rating 7 on the VEI scale was the 1815 eruption of Tambora in Indonesia, which caused tens of thousands of deaths locally and tens of thousands more worldwide due to the volcano's effects on the climate. Because of the ash that Tambora injected into the atmosphere the following year, 1816, is known as the year without a summer.

The most recent eruption rating 7 on the VEI scale was the 1815 eruption of Tambora in Indonesia, which caused tens of thousands of deaths locally and tens of thousands more worldwide due to the volcano's effects on the climate. Because of the ash that Tambora injected into the atmosphere the following year, 1816, is known as the year without a summer.

The average global temperature that year lowered by around half a degree Celsius, causing harvest failures and food shortages. VEI 7 eruptions like Tambora are few and far between. For another eruption of comparable scale, you have to go all the way back to 1257 and the eruption of a volcano called Samalas, also in Indonesia.

The average global temperature that year lowered by around half a degree Celsius, causing harvest failures and food shortages. VEI 7 eruptions like Tambora are few and far between. For another eruption of comparable scale, you have to go all the way back to 1257 and the eruption of a volcano called Samalas, also in Indonesia.

The average global temperature that year lowered by around half a degree Celsius, causing harvest failures and food shortages. VEI 7 eruptions like Tambora are few and far between. For another eruption of comparable scale, you have to go all the way back to 1257 and the eruption of a volcano called Samalas, also in Indonesia.

But if the largest eruptions in recorded history only reach a VEI of 7, what sort of events could warrant the top rank on the scale? VEI 8 eruptions, given the adjective mega-colossal by volcanologists, are those produced by so-called supervolcanoes.