It’s common knowledge that Iceland has its fair share of volcanoes, it being an island that sits astride the Mid-Atlantic Ridge on the northern reaches of Europe. Numerous of these volcanoes have been active in the last century, with most people, for example, being familiar with the chaos caused by the ash-cloud of the 2010 Eyjafjallajökull eruption. What is making the headlines at the moment however, is something a bit different: the possibility of a new volcanic vent opening up within a town of 4000 people. In fact, the Icelandic Met Office is currently issuing the warning: “Significant likelihood of a volcanic eruption in the coming days”.
Eyjafjallajökull eruption of 2010 (source).
So what is going on?
On 25 October 2023, a swarm of earthquakes was detected just north of the town of Grindavík, and by 26th October, over 4000 such events had been recorded (see map below). This period of activity was interpreted as being associated with the accumulation of magma, as a dyke, beneath the Reykjanes Peninsula; something that seems to have been developing since 2021. Back in October 2023, the accumulation of magma within the crust was reflected at the surface with an uplift of up to 3 cm, centred very close to one of the country’s major tourist destinations: the Blue Lagoon.
Earthquake locations on 25 October 2023 (source).
On 30 October, the depth of the magmatic intrusion was estimated to be 4 km and there were concerns that fracturing of the crust, caused by the many earthquakes, could facilitate the migration of this magma to the surface. Such activity continued over the coming days, with uplift reaching 7 cm by 6 November, and magma inflow estimated at 7 m³/s (around four-times greater than inflows measured for the most recent events). And this brings us up to the current situation, which is seeing around 1000 earthquakes, daily, mostly at a depth of 3-3.5 km, and with uplift now being clearly visible within Grindavík, resulting in significant damage to fixed infrastructure.
Cracks in the road in Grindavík, caused by rising magma (source).
Is there any precedent for this event?
Back in 2021, similar events occurred about 8 km away, at Fagradalsfjall, resulting in the eruption of lava at the surface. Current fears are that such a Fagradalsfjall-type scenario is about to be repeated, but rather than occurring in a remote and uninhabited location, this time, such an eruption could occur within the town of Grindavík itself. Such an event could be devastating for the town, and indeed, for the nearby tourist infrastructure. Indeed, the nearby Blue Lagoon was closed on 9 November, following safety concerns associated with the frequent earthquake events, which had seen rocks dislodged onto the resort’s access roads.
So what might the future hold?
Scientists and disaster managers are currently warning that an eruption is imminent. This eruption, it is proposed, could begin anywhere along the 15 km inferred location of the intrusive dyke, which skirts Grindavík and also passes little more than 1km from the Blue Lagoon. There is also the possibility that the eruption of lava could be submarine – something that could generate particularly explosive, and ash-generating, phreatomagmatic volcanic activity. Another concern is that the line along which the eruption of lava is likely, passes the Svartsengi geothermal plant, which provides electricity and water to local residents.
The location of the dyke-induced fissure present on the Reykjanes Peninsula. Any lava eruption will likely effuse from somewhere along this fissure (source).
Prior to 2021, volcanism on the Reykjanes Peninsula had been undocumented for nearly 800 years. Indeed, the Icelandic sagas mention ‘fires in the sea’ at the Reykjanes Peninsula in the 13th century. The more recent Fagradalsfjall event however, seems to reflect a reawakening of activity in the region, with eruptive events also occurring in 2022 and as recently as July 2023. Perhaps alarmingly, if history repeats itself, activity on the peninsular could continue for up to 400 years, as it did in past centuries. As readers will be aware, volcanic activity is inherently unpredictable, and such a prolonged period of activity is far from being certain, but the Icelandic authorities will certainly be aware that they may be in this for the long-haul. For now, however, we just have to sit and wait, and watch mother-nature do her thing, on this island which, indeed, owes its very existence to the occurrence of such activity.