Volcanologists warn of the risk of a large eruption that “devastates global society”

The two experts sign an opinion article in which they draw attention to this risk. ‘Data from ice cores on the frequency of eruptions over time suggests that there is a one in six chance of a magnitude 7 explosion occurring in the next hundred years. “That’s a roll of the dice,” warns Mani. These gigantic eruptions have caused sudden climate changes and the collapse of civilizations in the past, the authors warn.

In 2021, the Tajogaite volcano (La Palma) reached an explosiveness index of 3 on the scale of 8 that measures the magnitude of an eruption. Level 4 was the Eyjafjallajökull (Iceland), which in April 2010 forced the cancellation of more than 20,000 flights in northern Europe. The eruption of the underwater volcano Hunga Tonga last January was magnitude 5, like that of Vesuvius that devastated Pompeii and Herculaneum.

Volcanoes and asteroids

The Hunga Tonga, Cassidy and Mani highlight, threw ash hundreds of kilometers and caused losses equivalent to 18.5% of Tonga’s GDP, in addition to “tsunamis that reached the Japanese, North American and South American coasts.” Fortunately, it only lasted about 11 hours,” they say. “The Tonga eruption was the volcanic equivalent of an asteroid that narrowly missed the Earth, and should be considered a wake-up call,” says the CSER researcher.

The Krakatoa (Indonesia) eruption of 1883, which killed more than 36,000 people, was level 6. And the Santorini (Greece) eruption of 1628 before the Common Era was of magnitude 7, which could have been behind the collapse of the Minoan civilization, and that of Tambora (Indonesia) in 1815. In the latter, “it is estimated that 100,000 people died, and global temperatures dropped by an average degree, causing massive crop failures that caused famines, violent revolts and epidemics in the which became known as the year without a summer (1816),” Cassidy recalls.

Mani equates the risk of a massive eruption with that of a kilometer-long asteroid impact, which astronomers believe could wipe out civilization. Although the climatic effects are comparable, “the probability of large-scale volcanic eruptions occurring over the next century is hundreds of times greater than that of recorded asteroid and comet impacts,” volcanologists point out.

“Hundreds of millions of dollars are spent each year on the asteroid threat, but there is a serious lack of funding and global coordination for volcano preparedness. This must change urgently. “We are completely underestimating the risk that volcanoes pose to our societies,” warns Mani. That of Tambora in 1815 is the last magnitude 7 eruption recorded, but now, Cassidy indicates, “there is eight times more population and more than forty times more level of commerce. “Our complex global networks could make us even more vulnerable to the impact of a major eruption.”

No data on many eruptions

The authors believe that investment is needed in the prediction and management of such an event, as well as in the mitigation of less violent eruptions. They highlight that we only know the location of a handful of the 97 large-magnitude eruptions in the last 60,000 years. That means, they warn, that there could be dozens of dangerous volcanoes spread around the world with the potential for extreme destruction whose existence we have no idea about.

“We may not even know about relatively recent eruptions due to a lack of investigation of marine and lake cores, especially in neglected regions such as Southeast Asia,” says Cassidy. “Volcanoes can remain dormant for a long time, but remain capable of sudden and extraordinary destruction,” she adds.

According to Cassidy and Mani, only 27% of the eruptions recorded since 1950 have been monitored with instruments such as seismometers. Furthermore, only a third of this data has been uploaded to the World Volcanic Disturbances Database (WOVOdat), when controlling seismicity, gas emissions and terrain deformity could be used to predict eruptions. And they remember that, among other things, the volcanological community has been demanding for more than 20 years that a satellite be dedicated to monitoring these phenomena.