Even minor volcanic eruptions could trigger global disaster, scientists warn



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The specter of terrifying volcanic eruptions has been etched in our imaginations from childhood: a shattering explosion, followed by spurts of lava and smoke.

The dangers of large-scale volcanic eruptions are very real: in the worst-case scenario, an extremely rare and powerful supervolcanic eruption could even devastate the planet. But scientists now warn that it wouldn’t even take such extreme explosion to trigger a global catastrophe.

Much smaller-scale volcanic events can still trigger chaos enough to endanger the modern world, new research shows.

“Even a minor eruption in any of the areas we identify could erupt enough ash or generate earthquakes large enough to disrupt the networks that are at the heart of global supply chains and financial systems,” says Lara Mani, researcher in global risks at the University of Cambridge.

“At the moment, the calculations are too biased in favor of giant explosions or nightmare scenarios, when the most likely risks come from moderate events that disable major international communications, trade networks or transportation hubs.”

Moderate eruptions might not grab our attention as much as their more thunderous counterparts, but they can wreak more havoc.

Case in point: The magnitude 6 eruption of Mount Pinatubo in the Philippines in 1991 was about 100 times more powerful than the magnitude 4 eruption of Eyjafjallajökull in Iceland in 2010.

But Eyjafjallajökull turned out to be the costliest volcanic eruption in history, with a $ 5 billion damage bill to the global economy – while losses from the much larger Mount Pinatubo eruption were just a fraction of that ($ 740 million in 2021, adjusted for inflation).

How is this imbalance possible? Mani and his team call it “VEI-GCR asymmetry”: a new type of paradigm where the danger of volcanoes (global catastrophic risk, GCR) does not increase with the power of volcanoes (volcanic explosiveness index, VEI ).

Historically, volcanic risk assessments have suggested that the more powerful a volcano’s eruptions, the greater the danger it presents in terms of overall catastrophic risk: a relationship that can be called “VEI-GCR symmetry” .

But that may no longer be the case, as most of the world’s critical infrastructure today – including international shipping crossings, submarine telecommunications cables, and air transport routes – are not particularly close to the volcanic regions that produce the most powerful eruptions (with an VEI of 7 or 8).

“We observe that many of these critical infrastructures and networks converge in areas where they could be exposed to moderate-scale volcanic eruptions (VEI 3-6),” the researchers write in their study.

“These regions of intersection, or pinch points, let’s showcase places where we have prioritized efficiency over resilience, and created a new global landscape of catastrophic risk. “

According to the team’s analysis, there are seven such “pinch points” around the world, where critical infrastructure pieces are now found dangerously close to VEI magnitude 3-6 eruptions.

These include Taiwan, which produces a huge amount of microchips around the world, whose global supply is compromised by proximity to the Tatun Volcanic Group (TVG).

In the United States, moderate eruptions in the Pacific Northwest have the potential to disrupt trade and travel to the United States and Canada, causing considerable economic damage.

Meanwhile, Icelandic volcanoes have the potential to create a pinch point in the North Atlantic, disrupting air traffic between London and New York, and causing serious delays for trade and transportation networks.

Other international pinch points, located in the Mediterranean and around Malaysia, threaten some of the world’s busiest shipping routes.

Another, located in the Luzon Strait, is a key route for submarine telecommunications cables connecting China, Hong Kong, Taiwan, Japan and South Korea – all of which could be damaged by eruptions causing landslides. terrain and underwater tsunamis, causing serious disruption to communication capabilities. and global financial markets.

These kinds of downstream consequences aren’t the first things that come to mind when we think about the destructive power of volcanoes, but maybe they should be, the researchers suggest.

“It’s time to change our view of extreme volcanic risk,” Mani said.

“We have to stop thinking in terms of colossal eruptions destroying the world, as Hollywood movies show. The most likely scenarios involve smaller eruptions interacting with our societal vulnerabilities and leading us to disaster.”

The results are reported in Nature Communication.

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