Volcanic eruptions can be incredibly disruptive, causing flight cancellations, communication issues and more.

The 2010 eruptions of the Eyjafjallajökull volcano in Iceland created ash clouds that severely disrupted air travel across western and northern Europe for six days, with more than 100,000 flights canceled.

“When we talk about volcanic ash, it’s not the same as ash that you produce in a campfire,” said Greg Valentine, professor of earth sciences at the State University of New York at Buffalo. “It’s actually small particles of rock that get thrown up into the air — sometimes 20 miles into the air — and they get distributed downwind. We think a lot about aviation, but there is also our electrical and telecommunications structure. Ash falling on power lines can mess up their ability to transmit electrical current.”

Many of today’s communication devices have not been exposed to volcanic ash, said Balz Grollimund, Swiss Re Ltd.’s Toronto-based senior vice president for North America.

“One thing we haven’t seen yet is the impact on utilities, electronics,” Mr. Grollimund said. “The ash tends to short-circuit electronics ... and there’s some potential we could see some issues from heavy ashfall on that front. We don’t know how cellphone networks respond, cellphone towers, how resistant they are to ashfall.” 

In situations where a volcano is well-monitored, “we can make pretty good forecasts on timescales that allow for disaster mitigation, such as evacuating populations,” Mr. Valentine said. “The problem is most volcanoes on Earth are not monitored.”

There has not been much modeling of volcanic eruptions because volcanoes vary in the way they erupt and often pose more than one hazard, said Stephen Sparks, professor at the University of Bristol’s School of Earth Sciences.

“It’s quite a complicated risk,” he said.

Roughly every two years a volcano with no historical record of eruption will erupt, Mr. Sparks said, adding that two-thirds of the Earth’s volcanoes are in a dormant state and it is very likely they will erupt again.