2023–2024 Sundhnúkur eruptions

2023–2024 Sundhnúkur eruptions
The 2023 eruption photographed by the Icelandic Meteorological Office on 18 December 2023
Volcano	Eldvörp–Svartsengi
Start date	18 December 2023 (2023-12-18)
Start time	22:17 UTC
End date	Ongoing
Type	Fissure eruption
Location	Reykjanes Peninsula, Iceland 63°52′45″N 22°23′14″W
Impact	Earthquakes, ground subsidence, lava fountains, lava flows; town of Grindavík heavily damaged and evacuated; damage to regional infrastructure; 1 presumed dead from ground cracking

The 2023–2024 Sundhnúkur eruptions are an ongoing series of volcanic eruptions in the Reykjanes peninsula, near the town of Grindavík, Iceland. As of 16 March 2024, there have been four eruptions between December 2023 and March 2024, following an intense series of earthquakes. Although localised, the seismic and volcanic activity have caused significant disruption across the western part of the peninsula.

The eruptions were preceded by an intense earthquake swarm in the Eldvörp–Svartsengi volcanic system that began on 24 October 2023, caused by a magmatic intrusion underneath the area. The frequency and intensity of the earthquakes dramatically increased on 10 November 2023, with 20,000 tremors recorded by that time, the largest of which exceeded magnitude 5.3. An evacuation was ordered in Grindavík, and large-scale subsidence in and around the town caused significant damage.

The first eruption started on the evening of 18 December 2023, at the Sundhnúkur crater row north of Grindavík, with lava spewing from fissures in the ground. The intensity of the eruption and accompanying seismic activity decreased early on 19 December, with lava seen spreading laterally from both sides of the newly opened fissures. The eruption was described as the largest in the Reykjanes Peninsula since the beginning of eruptive activity in 2021, with lava fountains, up to 100 metres (330 ft) high, and was visible as far away as the capital Reykjavík, 42 kilometres (26 mi) away. The eruption ended on 21 December, after the Icelandic Meteorological Office (IMO) said no lava was erupting after a flight over the volcano, but clarified that it was "too early to declare the eruption over".

On 14 January 2024, a second fissure erupted north of Grindavík with most of its lava steered away from the town by newly constructed protective barriers. A few hours later, a smaller third fissure opened less than 100 metres (330 ft) from the town inside the protection barriers, with its lava reaching and burning down three residential houses.

A third eruption began on 8 February 2024 about a kilometre (half a mile) north of Grindavík, in the same area as the December eruption, with a fissure about 3 kilometres (1.9 mi) long effusively erupting lava on top of earlier flows. It caused significant damage to infrastructure, leading to the declaration of a state of emergency.

A fourth eruption commenced on 16 March 2024, originating from a fissure approximately 3–4 kilometres (1.9–2.5 mi) in length. This event is considered more powerful than any preceding eruption on the peninsula since 2021, establishing it as the most significant in recent years. A magma intrusion previously occurred on 2 March but did not breach the surface, potentially delaying the onset of the current eruption. Given the timing between the last three eruptions, an eruption had been anticipated at the beginning of March. This eruption is still ongoing after more than a month and has proven to be longer-lasting than any observed since December.

One individual was reported missing after falling into a crevice resulting from seismic activity. The missing person report was filed by a work colleague who, upon returning to the site, discovered the individual's absence without any witnesses to the event. Despite extensive search efforts, no trace of the person was found before the search was officially called off two days later, due to the hazardous conditions faced by rescue workers.

Earthquakes

2023 Iceland earthquakes

UTC time	2023-11-10 18:00:56
ISC event	635891990
USGS-ANSS	ComCat
Local date	24 October 2023 (2023-10-24) (23 days)
Magnitude	5.3 Mw(largest tremor)
Depth	2–10 kilometres (1.2–6.2 mi)
Epicenter	63.955°N 22.358°W / 63.955; -22.358
Areas affected	Reykjanes Peninsula, Iceland
Max. intensity	MMI VIII (Severe)
Casualties	1 missing

Map of volcanic systems on the Reykjanes Peninsula. Grindavík is at the southern end of the Eldvörp-Svartsengi system (marked here as 2)

Annotated view of area involved in 2023 seismic disturbances

The Reykjanes Peninsula, located in southwestern Iceland, has entered a new volcanic cycle after a period of approximately 800 years of relative inactivity. This resumption of activity was signaled by increased seismic and volcanic activity near the hyaloclastite mountain Þorbjörn beginning in 2019. Volcanic cycles on the peninsula typically last 300 to 400 years, with eruptions occurring at six to seven separate locations, including areas near the Capital Region. Individual eruptions within a cycle can persist for 10 to 20 years, with activity shifting to other sites every 30 to 50 years. Based on historical patterns, the current cycle is expected to continue until approximately 2300-2400 CE.

The Eldvörp-Svartsengi volcanic system has experienced 10 magmatic intrusions since December 2019, seven of them since October 2023. Four of these intrusions have resulted in volcanic eruptions, while prior ones did not reach the surface. Previous volcanic unrest during this period had been predominantly associated with the Fagradalsfjall system, where three out of five magmatic intrusions led to eruptions. Since 2021, there have been a total of seven identified volcanic eruptions on the Reykjanes Peninsula.

Iceland frequently experiences earthquakes due to its position on the Mid-Atlantic Ridge, where the Eurasian and North American tectonic plates meet. However, the 2023 swarm was unusually extensive and is linked to a magmatic intrusion approximately 15 kilometres (9.3 mi) long, extending southwest from Kálfellsheiði [ˈkʰaulˌfɛlsˌheiːðɪ] and aligning with the Sundhnúkur [ˈsʏntˌn̥uːkʏr̥] crater chain at a depth of roughly 800 metres (2,600 ft). The largest earthquakes originated beneath the Sundhnúkur craters, then spread southwestward beneath the town of Grindavík and offshore. Grindavík lies on lava flows from the Sundhnúkur crater chain's last eruption approximately 2,350 years ago and is one of six Reykjanes Peninsula communities located on or near eruptive fissures.

October 2023 earthquakes

From 24 October to 31 October, the Reykjanes Peninsula was engulfed in a significant seismic episode, beginning with an intense earthquake swarm on the evening of 24 October around the Þorbjörn and Svartsengi areas, attributed to magmatic intrusion. This onset featured over 1,000 earthquakes, intensifying the seismic unrest that had seen the peninsula experiencing over 700 quakes earlier in the month, the strongest of which was magnitude 3.3. By 28 October, the situation escalated dramatically, with the IMO reporting a total of over 7,000 earthquakes. This count increased with an additional detection of around 1,300 earthquakes on 30 October alone, pushing the cumulative tally even higher. The earthquakes, primarily at depths between 2–3 kilometres (1.2–1.9 mi), focused their intensity around the Eldvörp–Svartsengi region, north of Grindavík. Throughout this tumultuous period, the IMO, alongside Civil Defense and local stakeholders, maintained close surveillance of the seismic activity.

The first signs of a magma intrusion near the Svartsengi area, located northwest of Þorbjörn on the Reykjanes Peninsula, were detected in October. This phenomenon, identified through the latest GPS data and InSAR images derived from satellite data, indicated an accelerated rate of land rise, centred near the Blue Lagoon, approximately 1.5 kilometres (0.93 mi) northwest of Þorbjörn. It was the fifth occurrence of such land uplift in the area since 2020, suggesting increased pressure likely due to magma intrusion. The rapid uplift raised the likelihood of more frequent seismic activity in the area that could potentially allow magma to move closer to the Earth's surface. Experts conducted models to estimate the depth and size of the intrusion, amid expectations of a potential volcanic eruption within the next year.

November 2023 earthquakes

Sundhnúkur craters seen from the south-west

Hagafell (left foreground), viewed from Þorbjörn

The largest of the earthquakes to date reached magnitude 5.3 on 10 November. By this time, over 22,000 earthquakes had been recorded since the beginning of the swarm in October. The IMO predicted that an eruption was likely, stating that "it will take several days (rather than hours) for magma to reach the surface". The greatest extent of the magma intrusion was inferred to be around the Sundhnúkur crater chain, approximately 3.5 kilometres (2.2 mi) north of Grindavík. Instruments detected the presence of sulfur dioxide in the atmosphere on 14 November, indicating that magma was only a few hundred metres (a couple of thousand ft) under the surface. Although the number of earthquakes decreased somewhat since 10 November, the IMO was still recording between 700 and 1,000 earthquakes daily by 14 November.

Ground deformation sensors at Festarfjall [ˈfɛstarˌfjatl̥] and Svartsengi recorded that the ground had moved apart by 120 centimetres (47 in). Satellite measurements recorded the subsidence by about 1 metre (3 ft 3 in) of a swathe of land measuring approximately 5 kilometres long and 2 kilometres wide (3.1 by 1.2 mi), running from the Sundhnúkur craters to the western side of Grindavík. The creation of this graben-like formation on 10 November has enabled scientists to estimate the volume of the magmatic intrusion, which formed in a remarkably short period of 6 hours, as approximately 70 million cubic metres (2.5×10^⁹ cu ft). Further analysis revealed that about 7,000 cubic metres per second (250,000 cu ft/s) flowed into this magma intrusion, providing valuable insights into the dynamics of volcanic processes and the scale of subsurface magma movement. It is estimated that the subsidence has been continuing at a rate of about 4 centimetres (1.6 in) a day. A large crack opened up through the town, which old maps indicate is a reactivation of an existing fault. Scientists at the University of Iceland believe that the fault was created by the last Sundhnúkur eruption over 2,000 years ago.

Sensors emplaced in a borehole in Svartsengi detected the presence of sulfur dioxide on 16 November, a classic signature of magma close to the surface. This led the IMO to conclude that the area around the volcanic edifice of Hagafell [ˈhaːɣaˌfɛtl̥], approximately 2 kilometres (1.2 mi) north of Grindavík, is at the highest level of risk. A rapid 3 centimetres (1.2 in) uplift of the ground in the Svartsengi area was recorded from 18 to 21 November, likely indicating an upwelling of magma from a source 5 or more kilometres (3.1 or more mi) below the ground. An eruption was still regarded as likely on 21 November, but as seismic activity declined from 24 November, that likelihood also began to decline.

In November 2023, Benedikt Ófeigsson, a geophysicist at the IMO, posited that Fagradalsfjall, rather than Svartsengi, might be the source of volcanic activity near Grindavík, noting the difficulty in assessing the activity's depth, location, and magma volume amidst seismic disturbances. He anticipated that InSAR satellite imagery would clarify these uncertainties. Supporting Benedikt's hypothesis, Freysteinn Sigmundsson from the University of Iceland, in February 2024, observed that minor seismic activity near Fagradalsfjall indicated potential magma movement, hinting at a possible eruption. He highlighted the magma's potential new pathways, particularly its shift towards the Svartsengi system and the persistent pressure in Fagradalsfjall post-eruption. Additional evidence bolstering the theory comes from the pattern of land uplift in these systems. In Fagradalsfjall, an uplift began following the end of volcanic activity in early August 2023 and persisted until the end of October 2023. Notably, as this intrusion concluded in Fagradalsfjall, a fresh phase of land uplift initiated in Svartsengi around the same time. Scientists from Uppsala University appear to have confirmed the theory proposed by their counterparts at the University of Iceland.

According to Professor Magnús Tumi Guðmundsson, a geophysicist at the University of Iceland, the magma channel, approximately 2 metres (6 ft 7 in) wide, had undergone rapid solidification. Approximately 90% of the magma solidified within 10 to 15 days following the subsidence in November 2023, due to the cold nature of the Earth's crust. However, some magma near Sundhnúkur remains, posing potential risks for further activity should underground pressure increase. Magnús notes that while the magma cools quickly, the surrounding rock stays hot and weak, maintaining a state of geological vulnerability in the area for several months, necessitating ongoing caution and monitoring. If an eruption were to occur, it was most likely to take place in the area between Sýlingarfell [ˈsiːliŋkarˌfɛtl̥] and Hagafell mountains.

Significant land movements were recorded around the Svartsengi area during the subsidence, with a displacement of about 100 centimetres (39 in) to the west and 25 centimetres (9.8 in) to the north. During the evacuation of Grindavík on 10 November, the ground near Svartsengi initially descended by 35 centimetres (14 in) and subsequently rose by 25 centimetres (9.8 in). A GPS station at Festarfjall, situated east of Grindavík, underwent a shift of 60 centimetres (24 in) eastward and 40 centimetres (16 in) southward, along with an upward movement of 12 centimetres (4.7 in). Moreover, the GPS station in Grindavík, directly above the magma conduit, moved 30 centimetres (12 in) eastward. On 10 November, at the aforementioned location, there was also a dramatic drop of 100 centimetres (39 in), followed by an additional sinking of 20 centimetres (7.9 in).

December 2023 earthquakes

On 1 December the Reykjanes Peninsula, near Svartsengi in Iceland, experienced a notable decrease in seismic activity, primarily recording micro-earthquakes below magnitude one, mainly concentrated between Sýlingarfell and Hagafell. Despite this decline, continuous deformation observed at nearby continuous GPS stations suggested ongoing adjustments due to inflation within the Svartsengi area. By 6 December, geodetic modeling results indicated that the magma inflow to the dike formed on 10 November 2023 had likely ceased, significantly lowering the risk of an eruption along this dike. However, the continued accumulation of magma beneath Svartsengi indicated that the volcanic unrest was not concluded, with a potential for new magma propagation events and an increased eruption risk. Through mid-December, sustained, albeit generally weak, seismic activity around the area, including over 460 earthquakes with a notable magnitude 2.8 tremor near Hagafell, underscored the ongoing geological unrest. Despite a slowdown in deformation rates observed by 16 December, the situation remained dynamic, with the potential for further volcanic activity under close scrutiny by scientists.

It is most likely that the magma accumulating under Svartsengi is feeding the 15 kilometres (9.3 mi) Sundhnúkur crater chain, where the magma intrusion occurred. Deformations are still being measured at stations near the conduit, but it is believed that this is due to the land uplift occurring at Svartsengi. At the beginning of December, recent GPS data from the IMO showed that the land had risen above its level prior to the start of the earthquake series in end of October 2023. Professor Þorvaldur Þórðarson, a volcanology expert from the University of Iceland, theorized that this elevation could be attributed to a combination of tectonic movements and magma build-up. Notably, the pronounced terrestrial shifts on 10 November may have facilitated the migration of magma from deeper reservoirs to more superficial ones.

In the weeks following the subsidence, the volcanic activity at Svartsengi entered a new phase with increased chances of magma propagation and potential eruptions. The observed pattern suggested a possible repetition of events, where magma accumulating beneath Svartsengi feeds a dike beneath Grindavík and northeast towards Sundhnúkur, similar to the one formed on 10 November. In the beginning of December, the magma flow was accumulating under Svartsengi at a rate comparable to the flow of the Elliðaár river, or just a few cubic metres per second (several tens of cu ft/s). The magma was believed to be located at a depth of about 5–6 kilometres (3.1–3.7 mi).

The recent seismic trends at Svartsengi, characterized by varying intensities and a concentration of activity along a dike, closely resembled the seismic and volcanic patterns experienced during the Krafla Fires, which began in 1975. In these old eruptive series, the region witnessed over a period of ten years 20 distinct magma propagations, nine of which culminated in eruptions. These events were marked by varying magma volumes feeding the same dike, leading to different eruption scales. In Svartsengi, geodetic data showed a similar pattern of reduced magma volumes compared to levels observed before the 10 November dike intrusion, parallelling the smaller magma accumulations at Krafla that were sufficient to trigger new propagations and subsequent eruptions.

From the beginning of the earthquakes until 10 November, the land at Svartsengi elevated by more than 10 centimetres (3.9 in) within a span of 16 days. Following a substantial subsidence of 35 centimetres (14 in), a new phase of activity led to a land rise of 20 centimetres (7.9 in) over an equivalent 16-day period. This same phase then peaked at about 35 centimetres (14 in) before the first eruption on 18 December later that year, thereby reaching the same height as prior to the subsidence. Typically, the land undergoes a sharp descent before each intrusion and eruption, followed by a gradual ascent thereafter. The previously mentioned subsidence was caused by the movement of magma from Svartsengi, passing beneath Grindavík, and extending towards Sundhnúksgígar to the northeast.

March 2024 earthquakes

An earthquake swarm on 2 March 2024 was interpreted as a magma intrusion that did not reach the surface. Modeling calculations indicate that the magma intrusion was approximately 3 kilometres (1.9 mi) long, extending from Stóra-Skógfell to Hagafell. The magma within this intrusion lies at a depth of 1.2 kilometres (0.75 mi) at its shallowest point, reaching down to about 3.9 kilometres (2.4 mi). The calculations estimate that approximately 1.3 million cubic metres (46×10^⁶ cu ft) of magma flowed into Sundhnúksgígar during the magma transfer, significantly less than previous events where it was estimated that around 10 million cubic metres (350×10^⁶ cu ft) had flowed from Svartsengi into the craters. Magma typically seeks the path of least resistance to the surface, and it is challenging to ascertain what prevented this during the event. Potential obstacles in the magma's path, insufficient volume, or pressure to open a vent, or a combination of these factors could have played a role. The magma intrusion behaved differently from previous transfers, warranting further investigation to enhance understanding of the nature of such events in the area and to anticipate future developments.

Eruptions

December 2023 eruption

The 18 December 2023 eruption as photographed from a helicopter of the Icelandic Coast Guard. At the right in the background, Grindavík, Iceland, is visible

On 18 December 2023, an eruption occurred at around 22:17 UTC following a series of small earthquakes at around 21:00. The IMO pinpointed the origin of the eruption near Hagafell, about 4 kilometres (2.5 mi) north-east of Grindavík, and noted that the eruption stemmed from a fissure with a length of about 3.5 kilometres (2.2 mi), with lava flowing at a rate of around 100–200 cubic metres per second (3,500–7,100 cu ft/s) adding that seismic activity appeared to be moving towards the direction of Grindavík. An Icelandic Civil Defence official told the public broadcaster RÚV that the eruption had happened quickly and appeared to be "quite a large event".

Following the eruption, the Icelandic Coast Guard deployed a helicopter to the area to monitor activity. Numerous delays were reported at Keflavík International Airport, which remained open. The Blue Lagoon spa, which had reopened the day before, did not take bookings on the night of the eruption. Police raised the risk level while civil defence authorities warned the public not to approach the area while emergency personnel assessed the situation. By 19 December, the scent of smoke and ash was detected as far as 30 kilometres (19 mi) from the eruption site, raising fears that volcanic gases could reach Reykjavík by the next day. However, the gas would never extend to dangerous levels there; it could only cause mild discomfort at most. On the same day, the Icelandic Coast Guard rescued a man who had gotten lost near the eruption site using a helicopter. On 21 December, the IMO said no lava was erupting after a flight over the volcano, but clarified that it was "too early to declare the eruption over". Officials said residents of Grindavík would be allowed back into the town. This eruption remains the only one in the series that caused no damage to infrastructures.

January 2024 eruption

Aerial photograph of the eruption on 14 January 2024

On 14 January 2024 around 7:57 UTC, a second eruption began around 400–500 metres (1,300–1,600 ft) north of Grindavík following seismic activity that began from the Sundhnúksgígar crater. Fissures were reported to have opened up on both sides of the anti-lava defences, and it was estimated that lava would reach the town within 24 hours. A successful mission was launched to save several pieces of heavy machinery used to construct the barriers. The lava cut off one of the main roads leading into Grindavík. The initial fissure reached a length of up to 900 metres (3,000 ft).

Around noon, another fissure, measuring about 100 metres (330 ft), opened only metres (several dozen ft) from the outermost houses of the town and subsequently set three houses on fire before ceasing after a few hours. Evacuation orders were reimplemented in Grindavík, while the Icelandic Coast Guard deployed a helicopter to monitor the situation. Volcanic activity was seen to have “decreased considerably” by 15 January.

Evgenia Ilyinskaya, a volcanologist from the University of Leeds, told the BBC that the eruption suggested that the Reykjanes peninsula was likely entering a long-term period of frequent eruptions that could last for centuries, which she termed the New Reykjanes Fires after a previous occurrence in the 12th century.

February 2024 eruption

A photograph of the eruption on 8 February 2024

On 8 February at 6:03 UTC the third eruption started north of Sýlingarfell following intensive seismic activity that began 30 minutes prior. The eruption produced lava fountains measuring between 50–80 metres (160–260 ft) in height and a 3 kilometres (1.9 mi) high volcanic plume. A 3 kilometres (1.9 mi) long fissure opened in the same area as the December eruption, between the Sundhnúkur craters and the hill of Stóra-Skógfell, about 4 kilometres (2.5 mi) northeast of Grindavík. The lava was reported to be flowing rapidly east and west. Although it was at a safe distance from Grindavík, it caused serious damage to infrastructure in the vicinity. Unlike in the previous eruptions on the peninsula, the 8 February eruption produced quantities of black ash mixed with steam. This is theorised to be the result of groundwater boiling and mixing with magma to create ash. Volcanic activity subsided later in the day.

The IMO estimated that around 15 million cubic metres (530×10^⁶ cu ft) of lava were erupted on 8 February alone, representing a flow of about 600 cubic metres per second (21,000 cu ft/s). About two-thirds of it flowed west into the Svartsengi area, extending up to 4.5 kilometres (2.8 mi) from the eruption centre.

March-April 2024 eruption

Aerial photograph of the eruption near Grindavík on 16 March 2024

On 16 March at 20:23 UTC, the fourth eruption started between Hagafell and Stóra-Skógfell, with impressive lava fountains that were several dozen metres (a few hundred ft) in height. Both the Blue Lagoon and Grindavík were evacuated. A 3 kilometres (1.9 mi) fissure opened up, producing two lava flows going in different directions. The first was seen to be moving in a westward direction towards the Blue Lagoon and the Svartsengi power plant and reached Route 43 (Grindavíkurvegur) leading into Grindavík, raising concerns that it could damage fiber optic cables laid on the road and cause internet and telecommunications disruptions. The second lava flow was seen to be moving south, reaching the eastern protective walls of Grindavík at a speed of 1 kilometre per hour (0.62 mph). The IMO said the eruption was "significantly wider" than the eruption of the previous month, while a geophysicist who observed the eruption during a helicopter flight described the eruption as the "most powerful" of the current eruption sequence. A state of emergency was declared again over the region on the day of the eruption, but it was downgraded to Alert Phase on 3 April. Volcanic activity subsided the next day but continued.

Between 3 and 8 April, the average flow of lava was estimated at 3.6 ± 0.7 cubic metres per second (127 ± 25 cu ft/s), just over half the average flow of 6.6 ± 0.3 cubic metres per second (233 ± 11 cu ft/s) estimated from 27 March to 3 April. On 9 April, the area of the lava bed was 6.14 square kilometres (2.37 sq mi), and the volume was 31.3 million cubic metres (1.11×10^⁹ cu ft), with lava ponding and pooling in low relief areas around the single active spatter cone. The land rise continued with constant magma flow under Svartsengi. The hazard assessment remained unchanged.

There is an indication that magma is primarily emerging from a deeper chamber and bypassing the intermediate storage at 4–5 kilometres (2.5–3.1 mi) beneath Svartsengi, previously the exclusive reservoir for the last three eruptions. Such direct access from the deeper source, located at 8–12 kilometres (5.0–7.5 mi) depth, may explain the prolonged activity of the eruption. In early April, Professor Þorvaldur Þórðarson, observing the decline in thermal imaging signals and magma output, suggested the eruption was weakening. The darkening of gases and the halt in land uplift underscored a shift in the magma dynamics, now dominated by the deeper magma source. This pattern echoes the initial stages of the 2021 Fagradalsfjall eruption, marked by low magma activity. He also posited that a reduction in magma flow to below 2–3 cubic metres per second (71–106 cu ft/s) could herald the cessation of the eruption in the foreseeable future. Land uplift had halted when the March eruption began but resumed at the beginning of April at a slower pace than after the previous three eruptions. As a result, approximately half of the magma flow is now diverted to the shallower magma chamber, while the other half continues to the surface.

The eruption began with the shortest notice so far, marked by the fewest precursor earthquakes and the shortest time from these initial signs to the onset of the eruption. Moreover, it was initially noted to be more intense than its predecessors in the series, establishing it as the most intense volcanic activity observed since the Bárðarbunga eruption in 2014. It has also been the longest of the four eruptions since December 2023. Access to the area of the eruption has been prohibited. However, some tourists have still been caught and turned back, though this has not been a significant issue.

Wildfires

During the first weeks following the start of the March 2024 eruption, wildfires broke out on the Reykjanes Peninsula, specifically targeting areas in proximity to the sources of volcanic eruptions. The fires, unlike the extensive wildfires during the Fagradalsfjall eruption in 2023, which spread across vast distances, are presently contained within a localized region. However, very dry soil and gentle breezes raised the risk of the fires' spread, especially with lava temperatures soaring between 700–800 °C (1,300–1,500 °F). Firefighting efforts, characterized by manual labor and the strategic use of tanker trucks—including a notably powerful truck from the Rescue Team in Vík í Mýrdal— were undertaken between firefighters in Grindavík and the Fire Protection Services of Árnessýsla and Suðurnes, as well as the Þorbjörn Rescue Team. Emergency crews successfully gained control over the wildfires in beginning of April, with most of the flames having been extinguished.

Impact

Grindavík

Closure of the road to Grindavík

Grindavík is currently mostly abandoned due to the volcanic activity and its inhabitants have been evacuated, although they have been permitted to return for short visits to remove personal effects and goods from their homes and businesses. Additionally, homeowners are permitted to reside in their properties. This represents the first time that an entire community has been evacuated in Iceland since the eruption of Heimaey in 1973. Presently, it is difficult to predict when Grindavík will become habitable again; however, scientists anticipate that the current conditions could persist for months or even years. The current civil protection phase in the area is classified as "Alert Phase".

Following the 5.2 tremor on 10 November, a state of emergency was declared, and evacuation plans were put into effect for Grindavík. This culminated in the relocation of nearly 4,000 residents, almost 1 percent of Iceland's entire population. The Department of Civil Protection and Emergency Management deployed the Icelandic Coast Guard Vessel Þór to the area "for safety purposes". It also closed all roads to Grindavík except for emergency and evacuation purposes. On 13 November, authorities allowed residents to return briefly to the town to retrieve their belongings. Boat owners were also allowed to remove their vessels from the harbour. The Icelandic government sought to accommodate displaced residents in holiday homes and little-used properties during the emergency in November and December. The subsidence, faulting and earthquakes have caused widespread damage to properties and infrastructure in the town. Since the November disaster, subsidence, earthquakes, and lava flow have led to multiple disruptions in the town's electricity and hot water services. The seismic activity has received significant coverage by the international media.

Prior to the evacuation, reports emerged of individuals relocating due to the incessant tremors disrupting sleep and fears of potential consequences. During the evacuation, the Icelandic Red Cross provided accommodation for about 1,700 displaced residents at three emergency centres in Keflavík, Kópavogur, and Selfoss. Of these individuals, approximately 140 actually spent the night in these centres. The majority of the other displaced residents independently found alternative accommodations elsewhere. Furthermore, every individual in the Grindavík area received an SMS message from 112, Iceland's emergency service, with the headline "EVACUATION".

The Icelandic government had plans to assist around 700 residents, who are part of about 200 families, from the original 3,700 population of Grindavík. The project included purchasing up to 210 new apartments through two non-profit housing associations, primarily in the Reykjanes area and the Capital Region. This was to be supplemented by temporary financial support for increased housing costs, with the entire support system estimated to cost about 220–240 million ISK per month, subject to a three-month reassessment with extensions. This initiative represented a comprehensive effort to provide both immediate and sustainable housing solutions for Grindavík's displaced residents. On 1 December, the government, in partnership with the Government Property Agency, began seeking additional temporary rental properties from private and corporate owners to assist displaced Grindavík residents as part of a larger pre-established housing support program that includes wage and rental subsidies. A week later, a platform for Grindavík residents was launched online, targeting temporary housing in the Reykjanes peninsula, the Capital Region, and neighbouring municipalities. It enabled direct leasing between residents and property owners, supported by government rental subsidies.

In a collaborative response to the disaster and ongoing uncertainty in Grindavík, Iceland's major banks—Arion Banki, Íslandsbanki, and Landsbankinn, in partnership with Finance Iceland—agreed to waive interest and indexation on housing loans for Grindavík residents for three months. This relief applied to loans up to 50 million ISK. The measure aimed to provide equitable support, including options like deferred loan repayments. Each bank further outlined the specifics of these relief measures, ensuring they are tailored to the evolving needs of their customers in Grindavík.

On 23 February, the Icelandic government enacted a law to acquire all residential real estate in Grindavík, taking on all unpaid mortgages with a fund of 61 billion ISK. The operation, under the supervision of the newly established real estate company Þorkatla, aims to relieve the residents' distress and uncertainty following seismic activities since the previous November. The law also granted Grindavík residents until the end of the year to decide if they wish to sell their property to the state. Homeowners then have a right of first refusal to repurchase their properties within three years after the law's enactment. As of 27 March 2024, 546 residents of Grindavík had submitted requests to sell their residences to the government, involving a total of 930 properties.

As part of the government's comprehensive plan, which includes efforts by the Department of Civil Protection and Emergency Management to prevent freezing damages in houses and ensure that Grindavík remains functional and safe for future habitation, up to 100 electricians and plumbers were mobilized to conduct critical repairs and upgrades, mostly from November 2023 to February 2024. This initiative also involved essential infrastructure work to secure and maintain the electrical and plumbing connections between the town and the power station, especially in January, when Grindavík's water main was engulfed by lava from the eruption. Specialized teams were also deployed to fill in cracks and faults resulting from seismic activity.

The State Commissioner of Police, in consultation with the Police Commissioner in the Reykjanes peninsula, downgraded the risk level in Grindavík from Emergency Phase to Alert Phase, which was effective from 23 November 2023 until the December eruption. This decision, based on a new assessment by the Icelandic Meteorological Office (IMO), indicated a reduced likelihood of a sudden eruption in Grindavík. Residents and businesses in Grindavík were then permitted to enter the area between 7 a.m. and 9 p.m. to retrieve valuables, attend to their properties, and conduct business activities. However, the town remained closed to the general public and unauthorized traffic. Safety measures, including limited vehicle access with restriction on certain types of transportation, constraints on essential services and a prepared evacuation plan, were established. The area, under continuous surveillance, is still considered dangerous. Residents were advised to keep records of valuables taken and to contact their insurance companies, and to be cautious as houses might be unsafe. About 120-150 residents commute to work in the town each day. In December, a resident of Grindavík was in caught staying at his home with his wife for several nights and was threatened with arrest due to the regulations in place at that time. Following the town's evacuation, a state of emergency was declared with the onset of each subsequent eruption, highlighting the significant risk involved. Upon the conclusion of each eruption, the status was systematically reduced to Alert Phase.

In the aftermath of the November disaster, the town was subjected to stringent regulations, which included specific opening and closing times. However, in late February, the State Commissioner of Police granted near-unlimited access to the town, albeit with a clear emphasis on the fact that "residents and employees enter the town at their own risk". The chief of police further emphasized that Grindavík is ill-suited for children due to the absence of functioning schools, the compromised state of infrastructure, and possible hidden faults in the town. Access is still strictly limited to residents, employees, and authorized media personnel. While homeowners are permitted to stay overnight in their homes, the chief of police strongly advises against it. In the nights leading up to the March eruption, 5-10 homes were occupied.

To enhance the existing security measures, which involved sending SMS warning messages to residents in the zone, emergency warning sirens underwent testing prior to the March eruption. The warning sirens have not been sounded in Iceland since April 2000 after they were subsequently decommissioned. Instead of warning sirens, a dial-out system was developed for all mobile phones. The warning sirens were, among other things, decommissioned as they were considered expensive and unreliable in operation. The system currently comprises three sirens located in Grindavík, with additional sirens installed at the Svartsengi power station and the Blue Lagoon.

The main concern and risk in Grindavík currently comes from the extensive cracks and faults that have appeared, most of which formed during the subsidence in November. Before the event, authorities were cognizant of existing fissures; however, many structures and pieces of infrastructure were built over these old cracks, disregarding the potential for their reactivation after being dormant for more than 2,000 years. Specialists, including those from the Icelandic Road Administration, are actively monitoring and mapping both the newly formed and previously unknown or concealed cracks that could pose a risk to public safety. On 10 January, an employee engaged in sealing these cracks fell into what was apparently the largest fault, which runs directly through the centre of the town.

The earthquakes in Grindavík had a profound impact on infrastructure and residences, prompting over 500 reports of property damage to the Natural Catastrophe Insurance of Iceland. Of these, at least 74 properties were deemed uninhabitable, with three being completely destroyed by direct lava contact. Two weeks following the earthquakes, a thorough damage assessment was initiated and is still ongoing. The estimated total cost of the damages is up to 10 billion ISK. Prior to the Icelandic government's implementation of a law to purchase all residential properties in Grindavík, property owners facing irreparable damage to their homes were obligated to allocate a segment of their insurance compensation—earmarked primarily for on-site repairs or reconstruction—to cover a disposal fee. In cases where rebuilding at the original location was not permitted, property owners were then allowed to use their insurance proceeds to buy homes elsewhere.

Blue Lagoon

The Blue Lagoon and the Svartsengi power station behind it

The Blue Lagoon is currently open after admission resumed on 6 April. Operational hours are now subject to adjustments based on forecasts of wind conditions and gas emissions, potentially leading to temporary closures due to unfavourable air pollution from the eruption. The hot springs area has repeatedly been closed and evacuated due to the earthquakes and eruptions. Although it has not been significantly damaged, lava has engulfed nearby roads, necessitating the construction of new ones. The hot springs were closed for three weeks starting from the March eruption, due to their close proximity to the ongoing eruption nearby and the continuous release of toxic gases. The nearest lava front has halted and is currently less than 1 kilometre (0.62 mi) away from the Blue Lagoon, which is protected by a constructed barrier.

The site's management announced the site's closure to visitors from 9 to 16 November as a precaution following the earthquakes. Rocks dislodged by the earthquakes were reported to have fallen onto roads in the area, and 30 guests left the resort following a magnitude 4.8 tremor in the early hours of 9 November. In addition to these safety concerns, the closure was also implemented to reduce increased stress on staff. The management has assured that all staff will receive their full salaries during the closure period. Furthermore, guests who were evacuated as a result of the tremor will be provided with a full refund. Helga Árnadóttir, Director of Sales, Operations and Services at the Blue Lagoon, confirmed that the seismic activity at Svartsengi caused no visible damage or structural impairment to their facilities. The buildings, designed for earthquake resilience, remained intact and structurally sound.

The administrators of the Blue Lagoon extended the closure announcement five times after the evacuation in November 2023 due to continuing geological activity. Following permission from the chief of police, it reopened on 17 December. Prior to reopening, the staff were trained in evacuation procedures to ensure preparedness for any emergencies, while the administration prepared an evacuation process, expected to take around two hours in case of emergency. Additionally, guests were to be informed about the current situation. Despite the advertised closure, staff members of the Blue Lagoon were observed enjoying the spa's geothermal waters before it officially reopened.

The Blue Lagoon remained open for just two days before it closed again on 18 December 2023 after the first eruption commenced only 2–3 kilometres (1.2–1.9 mi) away. All guests and staff were evacuated from the site roughly one to two hours before the eruption. The Blue Lagoon reopened on 6 January, with all facilities back in operation by 10 January. However, it was shut down once again on 14 January and promptly evacuated, but reopened on 20 January. It was safely evacuated at the start of the 8 February eruption but the hot springs were subsequently cut off by a fast-moving lava flow engulfing a stretch of Bláalónsvegur, its main access road. On 16 February, the Blue Lagoon reopened after the Icelandic Road Administration constructed a new gravel road within the defense barriers surrounding the hot springs, restoring access that had been cut off by a lava flow from the recent eruption. The Blue Lagoon was temporarily closed and evacuated on 2 March in anticipation of an imminent eruption but reopened two days later after no eruption occurred. The Blue Lagoon was closed indefinitely from 16 March due to the onset of the current eruption, but it reopened on 6 April.

The chief of police states that maintaining operations at the Blue Lagoon is scarcely justifiable amidst the ongoing eruption due to the risk of air pollution compromising public health. Administrators, in consultation with authorities, regularly assessed whether it was safe to reopen the geothermal spa. On 20 March 2024, a staff member at the Blue Lagoon was hospitalized due to symptoms of poisoning amidst the eruption that began on 16 March, which had resulted in elevated levels of sulfur dioxide. The illness occurred while the employee was working at the hot springs. The worker is expected to make a full recovery.

Svartsengi power station

The Svartsengi power station in 2019

The Svartsengi power station is currently unoccupied and is being remotely controlled from the Reykjanes power station. It experienced minimal impact from the earthquakes, with the only damage being "the interior furnishings and exterior walls, as well as considerable cracking in pathways and remote areas of the site". The power station continued to maintain its usual production levels of hot and cold water, as well as electricity.

There is a risk that if lava engulfs the facility, approximately 30,000 residents on the peninsula, constituting about 8% of Iceland's population, would permanently lose essential heating and electricity. Construction of earth barriers began in November 2023, with the purpose of protecting the power station by redirecting future lava flows.

Before the January eruption, HS Orka, the operator of Svartsengi power station, introduced a novel early-warning system that may be a first in volcanic monitoring. This system issued an essential alert more than four hours before the eruption. Since November 2023, the boreholes, pre-dating their use in the advanced system, have been pivotal in predicting volcanic activities. Detecting pressure fluctuations, these boreholes have reliably signaled upcoming eruptions, demonstrating their pre-existing potential in volcanic surveillance and safety.

The eruption of 8 February produced a lava flow that came close to the power station. It cut off the northern access road to the geothermal plant (though the southern road was unaffected) and destroyed part of the Njarðvíkuræð pipeline supplying hot water from Svartsengi to Reykjanesbær, Suðurnesjabær, Vogar, and Grindavík. Around 20,000 people in the area were reported to have been cut off from the hot water supply. Residents of the peninsula were warned to use hot water and electricity sparingly. Keflavík International Airport was among the locations affected by the loss of hot water; schools similarly affected were closed. Despite significant damage caused by the eruption on local infrastructure, the Capital Region was unaffected as it operates within a different geothermal energy distribution system. The Icelandic government declared a state of emergency in response to the hot water crisis. While the Reykjanes power station and the wider Icelandic grid can supply electricity if the Svartsengi line is cut off, the capability to deliver hot water, a critical function of the Svartsengi power station, cannot be replicated. At the time of the eruption, temperatures in the area reached as low as -14 °C (6.8 °F). The shortages contributed to the closure of schools, public pools and sport facilities in the area on 9 February.

The repair and reconnection of the hot water pipeline was completed on the afternoon of 9 February, approximately 30 hours after it was breached, restoring the supply of hot water to the wider Reykjanes area. Workers managed to splice together the undamaged sections of the old pipeline with the new underground system, often working through the night. In the weeks leading up to the February eruption, workers had been constructing an underground bypass pipeline parallel to an older one, designed to be more resistant to damage from lava flows. The plan was to link the intact section of the old pipeline, unaffected by the lava, to the new underground pipeline at both ends, outside the recently formed lava field. Despite these efforts, the newly constructed bypass pipeline collapsed under the pressure of the lava flow late evening on 9 February. Immediately workers started to construct a new pipeline, which was placed on top of the fresh lava. Around 50 hours later, on 12 February, water began flowing through the new pipeline.

Barriers and roads

A preliminary plan for the protective barriers intended to shield the Blue Lagoon and Svartsengi power station

A strategic plan for the construction of protective barriers had been established well in advance of the recent seismic disturbances in the area. The commencement of this plan was placed on hold, as there was no pressing threat of a volcanic eruption, coupled with the significant environmental repercussions involved. However, on 10 November, due to escalating earthquake activity, a fleet of lorries began delivering materials to the predetermined site near the Blue Lagoon and Svartsengi power station. But this initial operation was soon put on hold owing to concerns about a potential eruption later that same day. The construction work was officially resumed on 13 November, following the Althing's approval of a bill proposed by then-Prime Minister Katrín Jakobsdóttir. Following this, workers began assembling filler materials into barriers at the planned sites. The construction of the barriers was almost complete when the 18 December eruption occurred. Once it was safe for workers to resume, they were quickly sent back to the site to finish the remaining filling work on the barriers.

The prospect of protecting the Njarðvíkuræð hot water pipe leading from the plant was considered extremely challenging, as it is situated above ground on stilts. Prior to the eruption in February, plans were established to bury a new underground bypass pipeline, shielding it from potential lava damage, and preparing it for potential connection to the ends of the old pipeline in the event of engulfment. The eruption on 8 February resulted in the destruction of a segment of the old pipeline just north of Svartsengi and the subsequent collapse of a section of the new underground bypass pipeline on 9 February. Svartsengislína powerline had previously been protected with barriers around the base of the masts; when the same eruption encircled the structures, causing no damage.

Construction of protective barriers around Grindavík, for which plans were already in place prior to the eruptions, officially began on 2 January. The project, initiated from the eastern end, involves erecting a barrier extending over 2 kilometres (1.2 mi). As the project approaches its final stages, the initial phase of construction aims to reach an average height of around 4 metres (13 ft), although this may vary in different locations. The design of the barrier, guided by lava flow simulations, specifically targets the areas at highest risk. Authorities decided to raise the height of the northeast barriers in response to the thickening lava field from the March eruption, which poses a risk of overspill. Construction crews will be working around the clock on this project. On 21 March, the advancing lava began to fill a stone quarry previously utilized for sourcing materials for the barriers. However, workers are still able to obtain materials from alternative locations. Additionally, recently solidified lava was used as a resource for assembling the protective structures.

Also under consideration is the construction of protective barriers for the town of Vogar, located in the northern part of the peninsula, after lava flow models indicated a chance of lava from the current eruption flowing north towards Route 41 (Reykjanesbraut) in the future. While Vogar and Route 41 are considered to have a low risk of being affected, Route 43 (Grindavíkurvegur), being closer to the lava front, was considered to face a medium risk in this scenario, prompting additional concern for its safety. On 14 January 2024, a lava flow engulfed Road 43 located south of Svartsengi power station and the Blue Lagoon. Subsequently, on 8 February and again on 17 March, the same road north of these landmarks was overtaken by lava. These incidents effectively severed the connection between Grindavík and the north peninsula, each time prompting the construction of a new gravel road over the freshly cooled lava within days.

In the early stages of the March 2024 eruption, the encroaching lava threatened Route 427 (Suðurstrandarvegur) as it amassed against the eastern protective barrier of the municipality and advanced towards the sea to the south. This put two of the three crucial roadways linking Grindavík at risk, sparing only Route 425 (Nesvegur). Concerns escalated over the possibility of the lava reaching the marine environment, which could have led to minor explosive reactions upon contact with seawater and the release of toxic gases, including hydrochloric acid (HCl), due to chemical reactions with the water. A zone extending 500 metres (1,600 ft) from the anticipated point of marine entry was deemed critically dangerous to human safety. However, these risks were allayed when the lava halted approximately 300 metres (980 ft) from Route 427, just days after the eruption began. Since then, the lava front has remained unchanged.

In response to these developments, the Icelandic government implemented a 0.008% additional property tax, levied on the fire insurance value of properties, to fund the construction of lava barriers on the Reykjanes peninsula and safeguard local infrastructure from potential volcanic eruptions. The temporary tax, which is intended to last for three years, came into effect on 1 January 2024, and is projected to raise nearly 1 billion ISK annually. The tax is scheduled to expire on 31 December 2026.

Injuries and fatalities

On 10 January, just before the second eruption, a worker went missing while finalizing the filling of Grindavík's largest fault, after the ground suddenly collapsed midway down the fissure, dragging the top fill and the worker into its depths. At the time of this incident, there were no witnesses present. A colleague, finding no one upon return, reported the disappearance, initiating a search. Despite utilizing 3D scanners and underwater drones in the 40-metre-deep (130 ft) fissure, with water found at 20 metres (66 ft), the worker was not located due to the fissure's treacherous confines. The search, which included up to 70 rescue workers from the Icelandic Association for Search and Rescue, was terminated on 12 January due to the hazardous conditions. Following the search, The Administration of Occupational Safety and Health opened an investigation into the incident. With the individual presumed deceased, this incident represents the first death in Iceland associated with a volcanic eruption since the Heimaey eruption in 1973.

On 20 March, an incident at the Blue Lagoon resulted in an employee suffering from gas poisoning, attributed to a substantial release of sulfur dioxide from the current eruption, which is about 3 kilometres (1.9 mi) from the geothermal spa. Despite security personnel being equipped with portable gas meters and the existence of several fixed gas meters across the hot springs area, the specific area where the incident occurred lacked proper monitoring. The affected employee required hospitalization but is expected to make a full recovery. The incident prompted the Blue Lagoon management to undertake a comprehensive reassessment of the site's safety measures. In response to the situation, police were dispatched to inspect the facility.

International media coverage and tourism

The recent volcanic eruptions on the Reykjanes peninsula created a negative impact on tourism in Iceland due to misleading news coverage by foreign media. Foreign media outlets focused on the state of emergency declared in Grindavík, which gave the impression that the entire country was unsafe. This led to cancellations and a decrease in new bookings and prompted Business Iceland to correct misconceptions and promote Iceland as a safe and unique destination, producing a Q&A video in collaboration with the IMO, and launching a marketing campaign in December. Furthermore, Lilja Alfreðsdóttir, Minister of Culture and Business Affairs, allocated 100 million ISK to a special marketing campaign. Lína Petra Þórarinsdóttir, Head of Tourism at Business Iceland, believes that the negative impact of the volcanic eruptions can be turned into a positive in the long term, with Iceland being promoted as a unique destination with a special natural environment.

Birgir Jónsson, serving as CEO of Play Airlines at the time, claimed that extensive international media coverage of the volcanic eruptions in Grindavík caused substantial financial damage to Icelandic tourism, costing billions of krónas, in lost revenue. He voiced concerns over the exaggerated portrayal by some foreign news outlets, using imagined headlines such as "Iceland on fire" and "Poison gas over Reykjavík" to illustrate how such depictions contribute to portraying an unnecessarily alarming image of Iceland. While there have indeed been reports from abroad of toxic gas moving towards the Capital Region, subsequent analyses show that the emissions from the eruptions posed no significant threat or toxicity to the area. Since November 2023, the Blue Lagoon has faced similar challenges, incurring losses of 5 billion ISK due to frequent closures.

Jóhannes Þór Skúlason, Managing Director of the Icelandic Travel Industry Association, said the earthquakes and volcanic eruptions on the Reykjanes Peninsula negatively impacted tourist traffic during the holidays. This led to a decrease in visitors over Christmas and New Year after the coverage led people both to call off trips to Iceland and lower-than-expected demand in January and February 2024 compared to 2023. According to figures by Statistics Iceland, registered guest nights in January 2024 were 13% fewer than in January 2023, or 390,000 instead of 450,000. Bjarnheiður Hallsdóttir, chairman of the same association, attributed the decline in part to the changed attitude towards travelling to Iceland, including the media coverage of the earthquakes in Grindavík.

Reactions

In a televised address following the 14 January eruption, President Guðni Th. Jóhannesson, who is nearing the end of his tenure, said that "a daunting period of upheaval has begun on the Reykjanes peninsula", but urged the need to continue taking "actions that are within our power", while "hope for as good an outcome as possible". He also urged citizens to "stand together and have compassion" for those displaced by the eruption. While serving as Prime Minister, Katrín Jakobsdóttir said the eruption was a "black day for all of Iceland", but added that "the sun will rise again", and expressed solidarity with those affected.

See also

• Geology of Reykjanes Peninsula
• List of earthquakes in 2023
• List of earthquakes in Iceland
• List of volcanic eruptions in Iceland

External links

• Icelandic Meteorological Office—Official website (in Icelandic and English)