The next major volcanic eruption is capable of wiping out an entire city, killing millions of people and bringing global financial markets to a halt, according to a group of scientists.
In a recent paper published in Geosphere, a team of volcanologists broke down the consequences of not preparing for an inevitable volcanic eruption that ranks 7 or more on the Volcanic Explosivity Index (VEI).
These massive eruptions occur, on average, twice every 1,000 years, according to the study.
The last major eruption (size VEI 7) happened in Indonesia in 1815 and several more eruptions on that scale occurred in the centuries before (1,450, 1,257, 946).
“The next VEI-7 eruption could occur within our lifetimes, or it could be hundreds of years down the road,” Chris Newhall, a volcanologist and lead author of the paper, told Nature. He said it’s important that researchers and government officials start planning and preparing before an emergency strikes.
The last major volcanic eruption that happened in recent years was Mount St. Helens in Washington state in 1980, which was measured at VEI-5. Mount Pinatubo in the Philippines in 1991 was classified a VEI-6 eruption.
These disasters killed hundreds of people, expelled vast amounts of ash and gas high into the atmosphere and even caused global cooling.
However, the authors of the study said a VEI-7 eruption would be on an entirely different scale.
“It could destabilize financial centres, air travel, national economies and even peace between nations,” the authors wrote.
For example, an eruption of this scale happened in 1257 in Indonesia when the Samalas volcano exploded. The explosion released enough sulphur and halogen gases into the stratosphere to cool the planet in the second half of the 13th century (known as the Little Ice Age).
The authors said the event caused a “significant global effect” on food crops, causing widespread famine in Europe.
“England was hard hit and archaeologists have now discovered mass graves with more than 10,000 skeletons at Spitalfields in London, dating close to 1258,” the study said.
What if a massive volcano erupted soon?
If a VEI-7 eruption happened today near a large municipality, the researchers suggest it could erase the entire city. Hot ash, gases and lava from the eruption can travel up to 100 kilometres in any or all directions from the volcano, according to the authors.
“Any town or city in the path would be destroyed, and death tolls could reach millions unless mass evacuations had been made,” the study stated.
WATCH: Guatemala’s Santiaguito volcano erupts with massive pillar of smoke and ash
The hot ash and lava could also enter the sea and trigger tsunamis that can travel for a few hundred kilometres and wipe out coastal communities, the authors added.
“Given the incredibly complex logistics of food, water, health care and other supplies in an urban area, imagine the logistical nightmare if transport within any large city were stopped even for a week or two. Millions of hungry people do not stay quiet for long. National leadership may be challenged and replaced,” the study stated.
The authors used an example of the volcanic eruption of Eyjafjallajökull, in Iceland in 2010, which ranked at only a VEI-3. The ash from the volcano grounded air traffic for days and caused around US$5 billion in economic losses.
How to better prepare
The authors of the study say governments and companies should do more research on the changes in atmospheric moisture and the dispersion of volcanic ash on global positioning systems.
An early alert system should also be implemented for aircraft and trains, supply chains adjusted, nuclear power plants put into precautionary safe shutdown and food stockpiles increased, the researchers added.
They also identified a number of potential candidates for the next VEI-7 including Iran’s Mount Damavand or New Zealand’s Taupo, a supervolcano which was the site of the world’s last VEI-8 event. It took place roughly 26,500 years ago.
WATCH: How to prepare your family for a potential natural disasters