26-05-2025
Fighting fire with fire: Behind Iceland's lava barrier project
Iceland is already trying to innovate again by building barriers directly on top of fresh lava. This feat was previously deemed impossible due to the instability of new lava. PHOTO: ERIC TEO
– With steam rising over turquoise waters and black lava fields stretching to the horizon, the Blue Lagoon in Iceland promises serenity.
But just a stone's throw away from Iceland's most iconic spa, danger simmers in the form of the Svartsengi volcanic system, which has erupted eight times in the past two years.
After lying dormant for eight centuries, the Svartsengi system's first eruption occurred in December 2023 about 2.5km away from the Blue Lagoon.
Each eruption forced evacuations and closures, sending tremors through the nation's tourism industry.
But in November 2023, a new solution had begun to take shape in the form of lava barriers, made of solidified lava.
The barrier network, funded by the Icelandic government, is constructed from cooled lava dating back 800 years – remnants from the last time the Svartsengi system erupted.
So far, enough volcanic rock to fill 1,000 Olympic-sized swimming pools has been used in the construction.
Around 70 workers have been working around the clock to build these barriers, some of which are as tall as a seven-storey building.
When the most recent eruption occurred in April 2025, these walls were able to divert molten lava away from the spa, the nearby town of Grindavik and the critical Svartsengi power plant, which provides heat and electricity to over 30,000 homes and Iceland's main international airport.
To fund the project, the Icelandic government initially pledged 6 billion Icelandic krona (S$60 million) through a nationwide housing tax. The government funding has since nearly doubled to 11 billion krona.
Mr Vidir Reynisson, director-general of Iceland's Civil Protection and Emergency Management, said the success of Iceland's efforts to protect the nearby town from being scorched by lava is due to planning that began years ago.
After centuries of dormancy, seismic activity was first detected in the Reykjanes Peninsula in 2020. A study was done to determine whether a prolonged period of volcanic unrest was imminent.
'We also wanted to know which critical infrastructure we needed to protect and who would be at risk,' Mr Reynisson said.
The government then commissioned Verkis, Iceland's oldest engineering firm, founded in 1932, to explore possible solutions.
Ms Horn Hrafnsdottir, the project's lead engineer, was initially surprised by her new appointment given that her area of expertise was in hydropower plants and flood risks. Yet, her background gave her the expertise to repurpose a model that maps river currents to predict lava flow.
When another volcanic system nearby, Fagradasfjall, erupted in 2021 after the eight-century dormancy, Verkis decided to trial a lava defence system.
'There's no one-size-fits-all approach when it comes to lava protection systems,' Ms Hrafnsdottir noted. 'Each volcanic system poses different threats.'
Magma diverted from the town of Grindavik, a fishing town which had nearly 4,000 residents. It has been largely evacuated since November, but infrastructure has mostly been spared from lava damage due to the barriers.
PHOTO: ERIC TEO
The Svartsengi system near the Blue Lagoon is particularly unpredictable as it lacks a central cone, where volcanic material is usually vented.
Instead, magma from the system emerges through a fissure, which means that it can rupture at any point across the region.
After news of the eruptions in the area, travel agencies reported sharp spikes in cancellations, with many tourists postponing their visits and others cancelling their Iceland trips altogether.
'It's sort of a bucket list item. You go to Paris for the Eiffel Tower; Blue Lagoon is very much the Icelandic equivalent. So for our industry, it is important that the lagoon stays open,' said Mr Johannes Skulason, managing director of Iceland's Travel Industry Association.
Tourists still flock to the Blue Lagoon despite the risk.
PHOTO: ERIC TEO
The engineering team from Verkis reviewed other methods that can be used to protect people and infrastructure from lava, such as lava cooling, which entails spraying water on lava to slow down its flow, and aerial bombing, which aims to divert lava flow.
But they found that lava barriers – which have been used during eruptions in Hawaii and Mount Etna in Italy – showed the most promise. Their conclusion was based on laboratory tests, simulations and past case studies from around the world.
'This 2021 eruption at the Fagradasfjall volcanic system was in the middle of nowhere, and there was no risk to any infrastructure or inhabitants. It was our best chance to test the barriers out,' added Ms Hrafnsdottir, a civil engineer who has been with Verkis since 1996.
There, the team found that traditional lava barriers, which attempted to stop lava in its tracks, yielded mixed results. Although lava flow was delayed, some segments of the barriers were breached.
Thus, they pivoted towards a novel design that prioritised the diversion of lava away from key infrastructure instead.
The barriers were placed at an angle against the lava flow, yielding much more successful results.
In November 2023, volcanologists sounded alarm bells, pointing to imminent eruptions in the vulnerable Svartsengi area, which is close to key infrastructure such as the Blue Lagoon.
Although successful trials were conducted in 2021, they were much smaller in scale compared with the huge endeavour that the team had to undertake.
Dried lava from the Svartsengi volcanic system eruption 800 years ago is now being repurposed to build the lava barriers.
PHOTO: ERIC TEO
Ms Hrafnsdottir said that the lack of a successful precedent adds to the stress.
This marks the first time a lava diversion barrier has been deployed at this scale in the world.
'I am always asking myself if I am making the right decision,' she said. 'We do not have the privilege to go to some literature or refer to any standards.'
That burden of making decisions on the fly during an eruption then falls to the builders who execute the construction of the barriers, and who have grown accustomed to working under threat.
It took Mr Hjalmur Sigurosson and his team five eruptions since the first one in December 2023 to learn the ropes.
The managing director of construction at Istak, Iceland's largest construction firm, recalls the frenzy during the first eruption.
His team had parked their largest machinery in what they thought was the safest spot, away from the lava. However, the initial walls were not built high enough.
There were also gaps in the barriers that had to be plugged.
With lava rapidly approaching the equipment, however, Mr Sigurosson was forced to make a quick decision.
'We ran straight for the machines, brought them to safety and continued building the barriers higher when the lava was just metres away,' he said. 'We were running on pure adrenaline.'
It is business as usual at the Blue Lagoon, but the surrounding landscape has changed. Barriers are now visible throughout the area.
PHOTO: ERIC TEO
While the efforts have been successful so far, the country cannot afford to take its foot off the gas.
Experts forecast that the volcano could be active for up to three centuries.
'We are always going to wait for the next episode and the one after that. After each eruption, we always had to make some changes in the design and building of the barriers. We always need a plan B, C, D,' Mr Reynisson said.
While there is no end in sight, morale remains high among those involved in this engineering feat.
'I think everyone working on this project believes they are doing something for the greater good,' said Istak's Mr Sigurosson.
'That is the driving motor of the workforce.'
Eric Teo is a final-year undergraduate at NTU's Wee Kim Wee School of Communication and Information. This feature was prepared as part of the school's Going Overseas for Advanced Reporting (Go-Far) module in Iceland, which took place from July 27 to Aug 6, 2024.
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