From Vesuvius and the destruction of Pompeii in 79 AD, to the disruptive Eyjafjallajökull eruption of 2010 – Volcanoes are probably the most awe-inspiring but deadly natural disasters.
There are over 1,500 active volcanoes on Earth, with, on average, one erupting every week. But which of these explosions have been the largest?
We are looking at some of the biggest volcanic eruptions of the last 200 years, where figures and measurements can be far more accurate than in the distant past.
We have used the VEI (Volcanic Explosivity Index, a scale from 0-8) to compare the volcanoes' strength and the DRE (Dense Rock Equivalent scale) to measure the amount of material each eruption has produced.
10. Mount St. Helens (1980) – VEI 5, DRE 0.5km3
Deaths recorded: 57
On the morning of 18 May 1980, the Mount St. Helens volcano erupted with huge explosive force. It had been showing signs of gearing up for a big volcanic event for months, with a series of earthquakes indicating that magma inside was moving.
A bulge on the north flank of the volcano soon appeared, suggesting that an eruption was imminent. But no one could have predicted the sheer size of the explosion that followed.
When it came, it released a blast wave that reached speeds of up to 1,080 km/h, killing everything within an area of 600 km² in a matter of minutes. It remains to this day the most destructive and deadly volcanic eruption in the history of the USA.
9. El Chichón (1982) – VEI 5, DRE 1.1km3
Estimated deaths: 1,900
The El Chichon volcano in the state of Chiapas, Mexico, had long been assumed to be dormant, having not had a recorded eruption in over 600 years. However, in the first few months of 1982, it soon became obvious that this was not the case.
On 28 March, the volcano awoke with a huge eruption. Over the next few days, El Chichon seemed to go quiet, and evacuated residents started to return home.
The volcano wasn't finished, however, and on 4 April a deadly pyroclastic flow (a mix of hot gas, ash and rocks) was released. Many people living in villages near the volcano were killed, and huge amounts of sulphur dioxide were released into the atmosphere.
8. Mount Hudson (1991) – VEI 5, DRE 1.6-2.7km3
Human deaths recorded: 0
The Hudson volcano is one of the most active volcanoes in Chile, but its eruption in 1991 stands out as one of the most powerful in the 20th century. At the most explosive phase, it shot fragments of rock up to 18km into the sky, later falling on the Falkland Islands 1,000km away.
Thankfully local residents were evacuated when the first signs of activity started, so there was no loss of human life. However, the resultant ash that rained down on farmland near the volcano resulted in the death of thousands of grazing animals.
7. Quizapu (1932) – VEI 5, DRE 7-10km3
Deaths recorded: 0
On 10 April 1932, Quizapu erupted and released a huge cloud of ash into the atmosphere, along with large quantities of lava. The ash was carried over quite some distance, reaching parts of Argentina and showering them with small stones known as 'lapilli'.
Thankfully Quizapu is fairly remote, so there was little danger to human life when the volcano erupted. However, vegetation in the local area was destroyed and took over 60 years to grow back.
6. Hunga Tonga–Hunga Haʻapai (2022) – VEI 5.7, DRE 7.1km3
Deaths recorded: Six
On 15 January 2022, the underwater volcano Hunga Tonga–Hunga Ha’apai in Tonga erupted, causing its visible overseas structures to be completely blown off.
The volcano first emerged from the waves after a series of huge eruptions in 2014 and 2015, leading to the two islands' formation. These eventually joined together to make one solid land mass above the water.
The latest eruption ripped the whole island apart, generating a huge plume of ash that reached 20 km in the sky and led to a massive tsunami across the Pacific Ocean that resulted in the loss of six lives.
A NASA report found that a huge amount of water vapour was ejected into the atmosphere, making the hole in the Earth’s ozone layer much bigger in 2023.
5. Pinatubo (1991) – VEI 6, DRE 4.8km3
Mount Pinatubo volcano is located on the island of Luzon, the largest island in the Philippines. In mid-June 1991, a series of increasingly large eruptions unleashed huge columns of ash as well as dangerous pyroclastic flows and deadly hot mudslides over an area of hundreds of kilometres.
These flows filled valleys with huge amounts of magma, destroying towns and villages over a wide area. To make matters worse, Typhoon Yunya arrived in the Philippines just as activity at Pinatubo reached its peak. Dust and ash from the volcano combined with high winds, dispersing material from the eruption over a huge area and damaging large areas of farmland.
Thanks to early warnings and subsequent evacuation efforts, many lives were saved. But the effects of this hugely damaging volcanic eruption are still being felt today.
Deaths recorded: 1,202
4. Santa Maria (1902) – VEI 6, DRE 6.4km3
Estimated deaths: Between 7,000 and 13,000
After a long period of inactivity, the eruption of the Santa Maria volcano in 1902 seemed to take many locals by surprise. The warning signs (mainly several large earthquakes) in the lead-up to the eruption were ignored by residents, and many paid with their lives.
The eruption lasted 19 days and volcanic ash clouds were so intense that areas up to 160 km from the volcano were thrown into total darkness for 53 hours. Ash clouds even fell on San Fransico, USA, 4,000km away.
3. Krakatoa (1883) – VEI 6, DRE 9km3
Estimated Deaths: 36,600
The eruption of Krakatoa in 1883 is perhaps the most famous volcanic episode in history after Mount Vesuvius.
A series of immensely powerful explosions sent a deadly pyroclastic flow across the Sunda Strait at speeds of 100 km/h, killing everyone in its path. Tsunami waves were triggered with each explosion, the third of which has been calculated to be the loudest sound in history, at 310 dB. It is recorded that the sound was heard in Perth, Australia, over 3,000km away.
The ash released was so dense that it blocked out the Sun, lowering global temperatures for five years. It also changed the appearance of sunsets around the world, as seen in many famous paintings like Edvard Munch's The Scream.
2. Novarupta (1912) – VEI 6, DRE 13-14km3
Human deaths recorded: 0
The eruption that formed the Novarupta volcano in Alaska, USA, was the largest volcanic event of the 20th Century. During this three-day event, the eruption expelled thirty times the amount of material as the Mount St. Helens eruption of 1980.
Huge pyroclastic flows carved their way through the mountainous terrain, forming the Valley of Ten Thousand Smokes. Thankfully nobody was killed during this event, although wildlife (especially bird populations) suffered as a direct result.
This volcano and its surrounding area have been studied significantly over the last 100 years, as this was the first time in recorded history that a pyroclastic flow had remained on land.
1. Tambora (1815) – VEI 7, DRE 35-50km3
Estimated deaths: At least 71,000
The Mount Tambora eruption of 1815 is the biggest recorded volcanic eruption in human history. The volcano itself is located on the Indonesian island of Sumbawa and previously had been dormant for centuries. But this peace wasn't to last.
On 5 April 1815, the first of many eruptions started. Tonnes of ash were released, and the whole of the volcano was transformed into a mountain of fire. Large stones rained down on the surrounding areas, and whirlwinds generated from the sheer force of the volcano destroyed nearby villages. In total, these events lasted for over four months.
This cataclysmic eruption caused the height of Tambora to be reduced by one-third. Not only this but the ash and gases spewed out into the atmosphere in such high quantities it blocked out the Sun.
In the longer term, this led to massive food shortages globally, with 1816 becoming known as ‘the year without summer’. It is estimated that this one eruption ultimately cost the lives of at least 71,000 through starvation.
| Volcano | Year | VEI | Deaths | |
| 1 | Tambora, Indonesia | 1815 | 7 | 71,000 (Est) |
| 2 | Novarupta, Alasaka, USA | 1912 | 6 | 0 |
| 3 | Krakatoa, Indonesia | 1883 | 6 | 36,600 (Est) |
| 4 | Santa Maria, Guatemala | 1902 | 6 | 7,000 - 13,000 (Est) |
| 5 | Pinatubo, Philippines | 1991 | 6 | 1,202 |
| 6 | Hunga Tonga–Hunga Haʻapai, Tonga | 2022 | 5.7 | 6 |
| 7 | Quizapu, Chile | 1932 | 5 | 0 |
| 8 | Mount Hudson, Chile | 1991 | 5 | 0 |
| 9 | El Chichon, Mexico | 1982 | 5 | 1,900 (Est) |
| 10 | Mount St. Helens, USA | 1980 | 5 | 57 |
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