There is a volcanic eruption in Iceland approx. every 3-5 years. My research with communities surrounding the Eyjafjallajokull and Katla volcanoes shows Icelanders living in the vicinity of volcanoes generally have good knowledge of the hazard and risk and the response procedures they need to follow. However, evacuations are never easy.

Icelanders have a very strong connection to their land and their livelihoods, whether that be farming or the fishing industry, as is prominent in Grindavik. The government works closely with residents to ensure response plans are as streamlined as possible. Adjustments are made to allow residents back into evacuated areas for short visits, if considered safe to do so. This occurred during the Eyjafjallajokull eruption with authorities allowing residents back into the evacuation zone so that they could attend livestock. 

The recent surge in activity within Iceland’s volcanic area of Fagradalsfjall, is a good reminder of how ‘alive’ the Earth truly is and of its powerful societal impacts. Throughout geological timescales volcanoes worldwide have sculpted the Earth's surface, an ongoing process that continues to shape our world, whether we are prepared for it or not. Most people fear that the current volcanic activity in Iceland will have similar effects as the 2010 Eyjafjallajökull volcano eruption, which disrupted Europe’s air traffic for over a month by injecting large amounts of ash into the atmosphere. This happened due to magma coming in contact with ice atop the volcano. The conditions for an upcoming eruption in the Fagradalsfjall volcanic area strongly suggest the occurrence of a ‘fissure eruption’, this is, the lava will simply come out of a fissure and any aviation-related risks will mostly depend on whether the lava encounters the sea. If it does, an explosive cloud of ash and gases can form. At this point, it t is hard to predict if enough magma is going to erupt to reach the sea. The climate impacts of volcanic eruptions are intricate to predict. Typically, these are more likely to arise from very large volcanic eruptions, from more silica-rich magmas, which erupt more explosively, and can release gases directly into the stratosphere (12-40km). The upcoming eruption in Iceland is also unlikely to impact Australia, which is more susceptible to the influence of volcanic activity in Asia or in the Pacific region (e.g., Tonga volcano 2022 eruption). Therefore, it is crucial for Australia to engage in and promote collaboration with these countries in matter of volcanic monitoring as well as in volcanic-related research, in order to increase our understanding on this phenomena.

Impending Volcanic Eruption in Reykjanes Peninsula, Iceland  

The intense swarm of earthquakes signalling volcanic activity in Reykjanes Peninsula in southwest Iceland indicate we could see an eruption in a matter of days to weeks. Iceland is highly geologically active and has excellent monitoring, with experts on standby and locals evacuated.

The current volcanic activity is linked to the mid-Atlantic Ridge, where the Earth's crust is stretching and pulling apart. Beneath Iceland, a mantle plume (a column of hot rock that rises from deep within the Earth) is buoying up the ocean floor. However the magma involved in these eruptions is primarily basaltic, which usually does not result in massive ash clouds. While you could likely out-walk the magma flow, in some cases you might need to out-run it; depending on their composition, basaltic lava flows usually advance at less than one kilometre an hour, but can be much faster on steep slopes or if channelled through narrow paths. If the magma contains sufficient volatiles, fire-fountaining is possible but unlikely to be significantly more hazardous. Lava flows and fire fountains are pretty safe to watch but can do permanent damage to buildings and infrastructure.

Will this be like the 2010 Eyjafjallajökull Eruption? 

It’s very unlikely the impact of this eruption will extend further than the local area. The Eyjafjallajökull eruption occurred beneath a glacier and so interacted with water and ice, creating ash and particles that disrupted European air traffic for over a week. This type of eruption (known as phreatic) is not expected in the current situation at Reykjanes and is far less likely to produce large ash clouds that could impact air travel significantly.

Impact on travellers 

It is unlikely that travel will be impacted outside Iceland. Local towns might experience disruptions from lava flows and potential impacts on the local hydrothermal power system. Close to the site, eruptions could release volcanic gases like sulphur and carbon dioxide, causing local air quality issues. But while the eruptions could be a nuisance, they aren’t expected to be as hazardous or explosive as those in other volcanic regions like the Pacific Ring of Fire, where earthquake and volcanic activity occurs from tectonic plates converging, and can be extremely hazardous, as we saw in 2019 on White Island in New Zealand and last year’s Hunga Tonga-Hunga Haʻapai eruption. This is a very different scenario.

Volcanic eruption is highly likely, but not guaranteed. If it happens, we do not know when and where it will be, how long it will last and what the exact impacts will be. Activity since 2021 had low explosivity (like what we would expect in Hawaii, for example) however lava flows can engulf buildings and infrastructure as recently seen in La Palma, Canary Islands, in 2021. If lava flows reach seawater, there will be small explosions and toxic gases, but at local scale. This is different to the 2010 Eyjafjallajökull eruption where explosivity was driven by interaction between magma and a glacier. Therefore, volcanic activity is unlikely to affect air traffic or Aussies. 

A country built on volcanic land, eruptions in Iceland are common and expected. The Reykjanes peninsula has hosted three eruptions since 2021. However, a magma ‘intrusion’ is now detected underground close to the locality of Grindavík.  

Volcano monitoring and emergency management is based on three indirect ways of measuring magma movements under the surface: 

1) earthquakes - as magma pushes its way to the surface, it breaks rocks apart triggering seismicity. Importantly, the relative decrease in seismicity in the last few days does not mean there is no magma moving up but instead, could mean the magma has built its conduit and does not need to make space.  

2) land deformation, including satellite measurements. Millimetre to centimetre inflation can indicate magma moving towards the surface. Magma is now detected half a kilometre below the ground.  

3) chemistry of volcanic gas. Magma is a mixture of hot liquid, crystals, and gases, including water vapour but also CO2 and SO2. Increased SO2 levels could be related to the new magma intrusion, causing evacuation at Grindavík.

Iceland is a highly dynamic place, straddling a tectonic plate boundary at the ‘Mid-Atlantic Ridge’ – where rising hot magma from the deep Earth (the mantle) is slowly pulling Iceland apart. At different times, and in different locations, this magma can make its way to the surface in the form of volcanic eruptions.

In the case of Grindavík, the Icelandic Met Office is reporting that magma has now come very close to the surface, possibly around 500 metres. The ascent of this magma is what has led to thousands of ‘mini-earthquakes’ across the past few days – essentially the rocks within the Earth are ‘rumbling’ in response to this magma ‘forcing’ its way up through the crust.

Fortunately for us here in Australia, and others elsewhere, this eruption (if it occurs), will likely not cause the type of international disruption to air travel we experienced due to the 2010 Eyjafjallajökull eruption. In the case of the Eyjafjallajökull eruption, the ascending magma reacted with ice and glacial melt water, creating an enormous eruption column as a response to the meeting of molten rock and cold water/ice (called a ‘phreatomagmatic eruption) – this ‘recipe’ for disaster is not present at Grindavík.

It’s a hairy situation, but one thing in Iceland’s favour is that they have organised themselves really well for early warning systems and information flow. The Icelandic Met Office, which is responsible for geohazard and severe weather warnings, is a world leader in that respect.  We can help them out by ensuring that we only spread news from credible sources in Iceland (including the Icelandic Met Office https://en.vedur.is/ ), and avoiding spreading misinformation – and there’s a whole lot of online disaster tourism out there!

The imminent eruption in Iceland is unlikely to cause the chaos that we saw with the Eyjafjallajökull eruption, which interrupted regional air travel and had an economic cost of more than AU$2.5 billion. However, the 15-km-long magma chamber of this new eruptive zone will likely feed major lava flows that will threaten the town of Grindavik (population of 3,500) and nearby infrastructure, including a major geothermal power plant. Any eruption is likely to be ongoing for months, and possibly years into the future.

Although the Australian mainland has no active volcanoes, we do have a number of dormant volcanoes that could erupt in the future, hence the importance of having Earth Science university departments and local skills to monitor these and other natural hazards. Some of these Australian volcanoes have erupted in the last 5,000 years (such as Mt Gambier), and these past eruptions have been captured in the oral histories of First Nations peoples. It would likely surprise most people that the ancient Australian continent hosts incredibly geologically young volcanism, and we are yet to fully understand how and why this volcanism has occurred given the vast distance to the nearest tectonic plate boundaries.

In recent weeks, thousands of small earthquakes have rocked the Reykjanes Peninsula in south-western Iceland. The intensity of this seismic activity suggests that this could be the precursor to a new eruption. The significance of this event is that the possibility of an eruption threatens the coastal town of Grindavík, which is located 50km to the southwest of the capital Reykjavík and is home to around 4000 people. This has caused local authorities to evacuate residents from the area as the possibility of lava breaching the surface and affecting the town remains very high. 
 
In recent years, the Reykjanes Peninsula has seen frequent volcanic eruptions, such as the 2021-2022 Fagradalsfjall volcano, which was as a fissure eruption that formed spectacular lava fountains. Although details of the magnitude of the potential impending eruption are unclear, it is unlikely to be similar to the Eyjafjallajökull eruption in 2010 which released large volcanic ash clouds that caused wide-spread disruption to air traffic in Europe. The eruption back then was caused by a large and explosive volcanic eruption occurring under a glacier that generated massive amounts of ash to be released into the atmosphere. Instead, the type of eruption that could occur now will more likely take place underground and remain more localised along a fissure with less substantial risk of large ash clouds being generated. The threat to residents and tourism in Iceland will likely be limited unless lava breaches the surface and volcanic gases, such as sulphur dioxide, are released, which will be a localised health hazard to people in the region.