2021 was a busy year for volcanologists.
The two eruptions that got the most media attention were Fagradalsfjall in Iceland and Cumbre Vieja in La Palma, Spain.
The Icelandic volcano erupted first, back in March.
And even though it was expected thanks to monitoring measures, it was one of the most astonishing events of the year, according to experts.
“It’s the first eruption there since the 13th century, I think, on the Reykjanes peninsula. So that’s interesting. And in the past, the eruptions there have—if we look at the last 10,000 years or so—there have been eruptions and episodes that have lasted for a century or more, so this one could go on for a long time episodically,” says Clive Oppenheimer, Professor of Volcanology at the University of Cambridge.
The eruption, about 40 kilometers (25 miles) away from the capital Reykjavik, was not a threat to the population.
“It’s also interesting in that it was very clear that it was going to happen. So in terms of monitoring and eruption prediction, several months before there were swarms of earthquakes in that region, there was a swelling of the ground surface that was picked up with satellite instruments, and then the earthquakes became very intense, and there were hundreds a day,” says Oppenheimer.
The volcano became a tourist hotspot within days, the slow flows meant people could get close to action without too much harm.
Hundreds walked eight kilometers (5 miles) to access it.
Unlike the Icelandic eruption, Cumbre Vieja on the island of La Palma, in Spain, caused a lot of damage, and threatened the lives of inhabitants.
It started in September, and scientists believe it stopped or slowed down on Dec. 13.
When lava met manmade objects, it spelt danger.
“One of the particular hazards was that these banana plantations were being inundated with the lava. Very, very thick lava. It’s just burying everything. But it was igniting the sheets of plastic that I think are used to protect the bananas from the wind. And so there were kind of toxic clouds of this burning plastic, and it’s quite hazardous. I’d never thought of this,” says Oppenheimer.
The lava engulfed many buildings and houses.
More than 7,000 people had to be evacuated.
“Right now we feel powerless because you can’t do anything against a volcano, you can’t do anything,” said Daniel Álvarez, evacuated resident, and bar owner.
Lesser-known volcanoes were also active this year.
The Pacaya volcano in Guatemala started to erupt in early February.
In April, a thick layer of ash put a grey veil on the usually green forest landscapes of the island of St. Vincent in the Caribbean, posing a greater danger to the population than the eruption itself.
More than 6,000 people had to be rehoused in shelters.
In May, it was Indonesia’s Mount Sinabung’s turn to erupt—and it erupted again in July.
It spewed a thick column of volcanic ash 2.8 kilometers (1.7 miles) into the sky.
People were advised to stay 5 kilometers (3.1 miles) from the crater’s mouth and to be aware of ashfall and avalanches of volcanic debris.
The same month—more than 7,500 kilometers (4,700 miles) away—Congo’s Mount Nyiragongo erupted for the first time in nearly two decades.
According to the U.N. children’s agency, 5,000 people fled to nearby Rwanda, while another 25,000 sought refuge to the northwest.
At least 15 lost their lives.
On the other side of the planet, the famous Kilauea volcano in Hawaii also erupted in late September.
Although its 2018 eruption endangered the population, this year’s phenomena was contained to the volcano park of the island.
Officials said increased earthquake activity and ground swelling was detected, and so they raised the alert levels accordingly.
Since the unpredictability of volcanic eruptions causes disruption and poses significant danger to communities, there’s a lot of interest in research to forecast volcanic activity.
NASA researchers published a report in April stating that satellite data may help predict eruptions months—or even years—in advance.
NASA used instruments onboard satellites to analyze over 16 years of radiant heat from several volcanoes that have been active in recent decades.
They found that in the years leading up to an eruption, the radiant surface temperature over much of the volcano increased by around one degree Celsius, and decreased again after the eruption.
In Spain, where the Cumbre Vieja volcano was erupting since Sept. 19, the country’s largest supercomputer helped researchers make short and mid-term predictions.
Each morning for two hours, one of Europe’s largest supercomputers processed data from the eruption.
At 8 a.m., the predictions were ready to be analyzed.
But forecasting remains a challenging task.
“The point is that what you’re trying to do is to visualize something that you can’t see because all the pre-action is going on 3 kilometers (1,8 miles), 5 kilometers (3,1 miles), 10 kilometers (6,2 miles) or more down. And we don’t have direct access to it. So we need to make measurements at the surface of gas emissions, of the surface elevation because it might inflate before an eruption of earthquakes. And we can do these with ground-based instruments, satellite, drones,” says Oppenheimer.
And looking to the future, Oppenheimer says it’s safe bet to expect more eruptions next year.
“More of the same, we’ll see more volcanoes that have been dormant for some time, will come to life. Some of the old faithful’s, familiar names like Etna and Stromboli, they’ll continue doing their thing,” says Oppenheimer.
He says more need to be done to translate the knowledge we already have into action.
“We still need to make a breakthrough to really convert the scientific understanding to civil protection and protecting the communities that are threatened by volcanoes,” says Oppenheimer.