04-05-2025
Iceland plans for a more volcanic future as southwest enters new eruptive phase
Faced with the likelihood of future displacement and disruption from volcanic activity, Iceland has been creating new tools to protect residents and infrastructure. PHOTO: AFP
REYKJAVIK – When Kjartan Fridrik Adolfsson and his family fled their home in Grindavik, Iceland, in November 2023, they didn't know their evacuation would become permanent. For weeks the small fishing town of 3,800 people had been rocked by intensifying earthquakes, and authorities feared a devastating volcanic eruption could be imminent.
'We left with nothing but the clothes on our backs,' the 60-year-old accountant says.
Weeks later, fountains of molten rock burst out at the town's doorstep – part of a series of 11 eruptions that have hit the area since March 2021, with the most recent activity on April 1. The seismic shifts have torn fissures in the landscape, cracked roadways and damaged buildings, while lava flows have destroyed a handful of houses. Today, few residents remain in Grindavik, which is just 40km from Iceland's capital and largest city, Reykjavik.
Events like this aren't new in Iceland, a famously geologically active island nation that's home to more than 30 volcanic areas and hundreds of hot springs and geysers. Mr Adolfsson himself moved to Grindavik as a child after his family fled a 1973 eruption on Iceland's Westman Islands. But the country's southwest corner is entering a new eruptive phase that experts say will last for centuries.
Faced with the likelihood of future displacement and disruption from volcanic activity, Iceland has been creating new tools to protect residents and infrastructure.
These include building barriers to protect against lava, studies to better predict where it might flow next, and new methods to cool and constrain the molten rock. Thinking ahead, planners are reconsidering development patterns in the Reykjavik region, so the nation's capital can take new volcanic activity into account when it thinks about growth.
Build the walls
Geologically, Iceland is turning a corner. 'The eruptive phase we have just entered will last about 300 to 400 years,' says Mr Thor Thordarson, a professor of volcanology at the University of Iceland. 'We will be living with this threat long term.'
Iceland sits on a seismic hot spot, where the North American and Eurasian tectonic plates are slowly drifting apart. On average, an eruption has struck every three years since the beginning of the 20th century. Much of this activity has taken place in Iceland's remote interior, which is largely uninhabited. But the most recent seismic activity has been clustered on the Reykjanes Peninsula, which extends westwards from Greater Reykjavik and contains both the country's main airport and its most popular tourist attraction, the Blue Lagoon geothermal spa.
Six volcanic systems ripple beneath the peninsula, and after an 800-year period of dormancy, the area appears to have reawakened. 'We could have a pause for some months, years or even decades,' says Mr Thordarson. 'But volcanic activity will resume on the Reykjanes Peninsula very likely this century – the question is where.'
Vast reservoirs of magma lie beneath the stark basalt landscape, and it's not possible to predict exactly where the molten rock may emerge – here, lava erupts not from mountain peaks but from fissures that open in the ground. As activity eases in one system, it often flares up in another, sometimes years or decades apart. The area is also part of the most densely populated region in Iceland: 80% of the country's 400,000 residents live within an hour's drive of Reykjavik.
To minimise disruption in areas where volcanoes and people live side-by-side, Iceland has honed its expertise on building lava barriers. As soon as the most recent round of eruptions began, trucks and bulldozers moved in to construct long embankments made from rock and rubble. These breakwater-like structures are intended to halt the lava's path around Grindavik, the Blue Lagoon and the Svartsengi geothermal power plant, which supplies the Reykjanes Peninsula's hot water.
Stretching 13.5km and containing over 3 million cubic meters of rock, the network of protective berms were largely successful during the recent rounds of activity. But in Grindavik, several houses were destroyed after a volcanic fissure opened up on the other side of the barrier wall.
'This is by far the biggest such project worldwide,' says engineering geologist Jon Haukur Steingrimsson, who is supervising the ongoing barrier construction project.
It's a job that requires Mr Steingrimsson's team to work within metres of active lava flows whose surface temperature can reach 600 degrees and almost twice that at its core. 'Lava is really just a material like any other,' he says. 'You just have to learn how to work with it and you can't be afraid of it.'
Living with lava
You can see this pragmatic attitude in the Icelandic approach to managing volcanism. When slow-moving lava 'tongues' crawl across the landscape, threatening development, emergency workers can cool the edge of the advancing flow with pumped seawater, a technique developed in the Westman Islands to prevent molten rock from closing off the harbour.
Barriers can be built atop hardened flows to help shield roads and infrastructure. Mr Steingrimsson's team has also been able to rebuild roads that cross these tongues before the rock within has fully cooled.
It's a technique that could inspire authorities in other volcanically active places – already Japan's civil protection organisation has sent two groups to study what is being done in Iceland.
This knowledge may prove crucial in protecting towns like Hafnarfjordur, on Greater Reykjavik's southern edge. Here a neighbourhood and an aluminum smelter were built on a former lava field – an area by no means guaranteed to be hit by lava where preparations for that scenario are nonetheless worth carrying out. Barriers are being planned to minimise the damage from potential future eruptions.
The process involves some potentially difficult choices.
'We won't be able to save everything, but we can save a lot if the circumstances arise,' Mr Steingrimsson says. If areas vulnerable to volcanic activity continue to be built upon, the government might be obliged to 'define which areas there are of secondary importance and not spend money and effort on protecting them.'
Planning ahead
Part of these protection efforts involve simply working out where lava might flow.
The Icelandic Meteorological Office is currently developing a risk and hazard assessment for the Reykjanes Peninsula, prioritising the capital area. The work, which includes running lava simulations, will end in 2026, but the national weather service has already published its first overview.
The good news is that risk to life in the city itself is limited: As there are no active eruptive rifts within the area, residents should have time to evacuate before lava from elsewhere reached them. But the report warns that 'damage to buildings and infrastructure could be enormous, even total destruction'.
Seismic activity could knock out power and water utilities, block roads and trigger a cascade of related impacts. Should the city's geothermal district heating system go offline in the depths of winter, for example, pipes could freeze and burst, causing extensive damage to buildings.
For city authorities, the report will highlight the importance of planning around the danger zones.
'When the risk assessment is done we can start categorizing land in the capital area. It is important that residential areas are built in the most secure zones,' says Mr Haraldur Sigurdsson, Reykjavik's head of planning. 'Then you can trickle down the scale of importance.' Commercial and industrial activity such as warehouses, for example, could be located in the more vulnerable building zones.
Housing pressures
These risks will likely complicate Greater Reykjavik's future growth. The master plan for the area's seven municipalities is due for an update in 2026, and there is pressure to reduce housing costs by increasing the amount of land allowed for residential building.
Reykjavik, the largest municipality, has for years been pursuing a policy of densification over expansion, limiting the city's sprawl as its population grows. But critics have complained that the policy has slowed construction and driven up prices by preventing builders from accessing cheaper land on the outskirts of the city.
Mr Sigurdsson says that focusing development on safe zones within the existing city will continue, while 'the reawakening of the Reykjanes peninsula will likely call for the capital area to be developed more towards the north, further away from volcanic activity'.
Finding places to build can be a challenge, however. Reykjavik has long debated building housing on the current site of its domestic airport, a 140ha former British Royal Air Force base located just over a mile away from downtown, in one of the country's most expensive areas.
But finding an alternative location for the airport – which offers access to the capital to residents of smaller towns in Iceland as well as Greenland – is no mean feat. A site between the city and the country's main international airport at Keflavik, an hour away, was considered, but it's now in the possible path of lava. So is Keflavik itself, for that matter.
A wider rethink of where Iceland builds might thus be necessary, suggests Mr Thordarson. 'We need to have risk diversification,' he says. 'In my opinion it is uneconomical to have everyone accumulate in the same spot here in the greater Reykjavik area.'
Meanwhile, residents who have relocated from their former homes in volcanically active regions face an unsettled future. The natural catastrophe insurance of Iceland covers damage caused by eruptions or earthquakes, but not losses in market value when an area is deemed unsafe to live in.
This is complicated for places like Grindavik, where most homes remain undamaged but cannot be reoccupied safely. The town is small enough that the government has given homeowners 95 per cent of their home's insurance value to relocate elsewhere. With a rough cost of about 73 billion kronur (S$735 million), that policy would be harder to honor if larger towns are placed at risk.
In the meantime, those living in the lava zones are learning to come to terms with their displacement.
'Our hope is that these eruptions will stop so Grindavik can be a viable place to live again,' says Ms Arna Bjorg Runarsdottir, a former resident who moved to the peninsula's northern coast. 'We miss our old life. Whether or not we'll return, however, remains to be seen.' Bloomberg
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