Past Whispers: Iceland’s volcanic underbelly gained international attention in April 2010 after emissions from Eyjafjallajökull filled the skies with a cloud of thick ash that stopped European air traffic for six days.

While those nearest the glacier-veiled volcano enjoyed clear days and relatively little fallout, the impacts to air travel were far reaching, stranding thousands of travelers and calling into question the systems used to determine aviation bans.

The global nature of the disaster provided a platform for many discussions, including the sustainability of our interconnected economies, our ability to respond to unexpected events, and our sometimes paltry efforts to mitigate the actions of Mother Nature.

Recent Rumbles: Another Icelandic volcano was heard from far more recently—on August 16—when activity from the Bárðarbunga Volcano set off a swarm of 3,000 small but intense earthquakes, according to the Associated Press.

In response, the Icelandic Meterological Office raised the aviation color code for the volcano to orange, indicating the volcano had an increased potential to erupt. Roads in the vicinity of the volcano have been closed and the Icelandic Civil Protection Service issued an Uncertainty Phase, a warning that means events could lead to a natural hazard in the future.

Bárðarbunga, located in an unpopulated area, is part of Iceland’s largest volcanic system. It sits roughly 765 yards beneath the Vatnajökull icecap. Its last confirmed eruption occurred in 1910, according to the Smithsonian Institution’s Global Volcanism Program. Currently, geophysicists believe the magma is moving horizontally beneath the ice but could eventually reach the surface.

“We have known for some time that Bárðarbunga was going to do something – we just didn’t know what. Because it is covered in ice, we rely on instruments to reveal its behaviour,” Dave McGarvie, a volcanologist at The Open University in Edinburgh, told The Conversation. “The clues from the patterns of earthquakes and earth movements reveal two clusters where magma is moving towards the surface, and if it gets there it will erupt.”

Plume Possibilities: At the moment, it’s impossible to tell what an eruption at Bárðarbunga might look like, McGarvie said. Possibilities range from the magma remaining under the ice and causing little more than instrument readings to an explosive eruption that melts glacial ice and causes ash plumes and flooding.

“To the southwest of Bárðarbunga lie the rivers which produce much of Iceland’s hydroelectric energy, and a fissure eruption in this area could cause big problems,” McGarvie said. “Icelanders have long known about this possibility and have specific plans in place should this happen.”

What’s not likely to happen is a repeat of the 2010 Eyjafjallajökull incident, scientists say. That’s because the impacts of the Eyjafjallajökull plume were caused by a rare combination of lots of fine, easily transported ash; dry weather; and winds that carried the ash directly into well-traveled flight paths. Flight cancellations are also less likely, McGarvie said.

“There are two main reasons for this,” he told The Conversation. “First is that the old flight rules – avoid all ash – have been relaxed so aircraft can now fly when there is some (but not too much) ash in the sky. Second is that the Met Office revised its model that estimated ash concentrations in the atmosphere, so we now have more certainty about how much ash there is and where it is.”

For now, the world will have to wait and see what Bárðarbunga has to offer. Volcano watchers can keep up with the latest activity in a variety of ways (see this great collection of resources at Volcano Café), including a bird’s-eye view from the Icelandic National Broadcasting Service’s webcam.