Reykjanes Peninsula Volcanoes: Sundhnúksgígar Eruptions

March Eruption 2024

The March eruption on the Reykjanes Peninsula, initiated at 8:23 pm on Saturday, March 16th, marked the fourth significant volcanic event in the region since December. This eruption followed a brief period of tremors, with the Norwegian Meteorological Agency detecting a spike in seismic activity and landscape changes indicative of impending magma flow.

The emerging volcanic fissure, located between Stóra-Skógfell and Sýlingarfell, not only replicated the scenarios of the eruptions in February and December but also stretched over 3 kilometres, showcasing a remarkable and rapid release of lava.

This lava flow, directed westward across Grindavíkurvegur and then veering southeast along Grindavík's defences, signalled a threatening advance towards Suðurstrandarvegur in Reykjanes. In response to this potential threat, authorities were vigilantly enhancing the town's defences and safeguarding essential infrastructure to mitigate the impacts.

The volcanic activity remained stable for a week, showing its ability to maintain a steady intensity. This eruption distinguished itself by its length, surpassing the durations of the previous three eruptions since December 2023. After a week, the eruption at Sundhnúksgíga subsided from its initial strength. However, in its third week, the volcanic activity remains stable, showing its ability to maintain a steady intensity. This eruption distinguished itself by its length, surpassing the durations of the previous three eruptions since December 2023. 

The danger level stays the same due to the high levels of sulfur dioxide (SO2). It is important to note that the general public is not able to visit the eruption site at this time.

February Eruption 2024

An eruption commenced at 6:02 am on 8th February 2024, northeast of Sýlingarfell. This event marks the sixth volcanic eruption in five years on the Reykjanes Peninsula, and notably, the third eruption within a short span. 

Around half an hour prior to the eruption, a series of earthquakes began within the magma intrusion located to the north of the town of Grindavík. Earlier in the morning, the Blue Lagoon was evacuated due to the seismic activity preceding the eruption, and no individuals were present in the town of Grindavík when the eruption started. The location mirrors the eruption that occurred on 18th December 2023.

The fissure stretched 3 km in length, and lava flowed both east and west, but noticeably more to the east. By midday on 8th February lava had flowed over the hot water pipeline that extends from the geothermal power plant in Svartsengi to Njarðvíkur, resulting in supply issues in Reykjanes. The eruption has subsided significantly and there has been no visible activity since 8am on February 9th.

Fissure eruptions like this one, akin to all six occurrences on the Reykjanes Peninsula in recent years, do not disrupt flights to and from Iceland nor do they produce much ash. This stands in stark contrast to the events of 2010, when a distinctly different type of eruption occurred beneath glacial ice, resulting in significant ash production.

January Eruption 2024

An eruption just north of Grindavík, southeast of Hagafell, began at 7:57 AM on January 14, 2024. Making it the 5th eruption in the last four years.

Earthquakes began at the Sundhnúksgígar crater row in the early morning of January 14, with earthquakes moving to the town of Grindavík. Public safety was raised to an emergency level, and the small fishing town was evacuated.

The first fissure opened up around 900 metres from Grindavík. Unfortunately, the fissure opened up on both sides of a barrier wall that was built to protect the town from lava. Slowly lava flowed near the town. The good news is the remaining barrier wall directed most of the lava west, rather than south, towards Grindavík.

A new fissure opened at 12:10, 200 metres north of the town. Lava from this fissure entered the town only after flowing for an hour. The lava set fires and has covered at least three houses. 24 hours later, the flow from this smaller fissure has stopped.

By January 16, the first, larger fissure showed no sign of ongoing eruption. However, movement continues to be measured in the southern part of the magma tunnel under Grindavík.

The eruption sites and surrounding areas are at high risk as new fissures can open without warning. That was the case when the fissure opened at the border of Grindavík on January 14; No spikes or signs were seen on the measuring instruments.

Although the eruption has ceased, GPS sensors detect ground deformation in and around Grindavík, showing that the underground magma channel under the town is making the ground expand. Thermal images revealed that cracks in the ground to the southwest of Grindavík have grown much larger. The area remains dangerous.

December Eruption 2023

After months of anticipation and earthquakes, a volcanic fissure emerged with a bang on December 18th, 2023. The eruption was located close to Sundhnúkagígar, about four kilometres northeast of Grindavík town. The force of this eruption is larger than the previous three in this area. It is estimated that the lava flow rate was in the hundreds of cubic metres per second in the first two hours.  In the beginning, the lava was flowing outwards from both sides of the recently opened fissures.

The fissure, spanning about 4 kilometres, stretched from near Stóra-Skógfell in the north to near Sundhnúk in the south. It is nearly 3 kilometres from the southern tip to the outskirts of Grindavík.

The volcanic eruption soon lost its intensity on December 21, and scientists reported that there was no visible eruptive activity. However, hours later, there was still glowing lava in the channels.

During the eruption, the Communications Director of Public Safety, Hjördís Guðmundsdóttir, stated that this is not a tourist eruption and asks people not to try to go there. A translated quote from visir.is:

“There is a reason why we are asking people not to go there. This is a large eruption, and there is dangerous gas in the area. We are not playing Cry wolf; this is truly dangerous.”

Understand the Seismic Activity with Perlan

As Reykjanes simmers with volcanic activity, signalling a potential eruption, there's no better time to immerse yourself in the volcanic wonders of Iceland than now. Perlan stands as a premier destination for anyone fascinated by these natural phenomena. Our state-of-the-art volcano exhibition not only offers a rich educational experience but also provides an unrivalled, interactive journey through the fiery heart of Icelandic volcanology. 

Visitors can witness the raw power of volcanic eruptions and understand the forces that shape our planet, all within the safety and comfort of Perlan's innovative facilities. With expert guides and stunning visual displays, Perlan is the perfect place to gain insight into the unfolding events at Reykjanes, making it a must-visit for locals and tourists alike who wish to experience the might of Iceland's volcanic landscape up close.

Leading Up to the Sundhnúksgígar Eruptions

Between October 25 and 30, 2023, Iceland's Reykjanes Peninsula experienced a surge in seismic activity, with thousands of earthquakes, some reaching magnitudes of 4.5, primarily around the Stóra-Skógfell area, indicating subterranean magma movements. This activity, attributed to the aftermath of a previous eruption at Fagradalsfjall, was accompanied by satellite-detected ground uplift, signalling rising magma pressure. By the end of October, the area had recorded around 1300 earthquakes, prompting close monitoring by experts due to the significant geological instability caused by various underground forces.

In the following week, from October 31 to November 6, 2023, Mount Þorbjörn saw an unprecedented seismic swarm of over 10,500 earthquakes, with a peak magnitude of 4.5, indicating deep magma movements about 4 kilometres underground. This activity, coupled with a 7 cm ground uplift at Mount Þorbjörn, suggested the presence of a magma-filled fissure, similar to events observed between 2020 and 2022. The seismic activity during this period varied, with notable spikes on November 2 and 4, yet all quakes remained below magnitude 3.0.

From November 7 to 14, increased earthquake activity, ground deformation, and sulfur dioxide emissions north of Grindavík highlighted the rising threat of magma intrusion close to the surface. The situation escalated around November 10-11, leading to the evacuation of Grindavík and the declaration of an emergency level of civil protection. GPS data later showed a deceleration in ground deformation, suggesting a possible ascent of magma towards the surface. Despite this, approximately 1000 earthquakes were recorded on November 12, mainly north of Grindavík.

By late November, seismic activity on the Reykjanes Peninsula began to wane, with a significant decrease in earthquake numbers by the end of the month. However, continuous uplift near Svartsengi suggested ongoing magma inflow, albeit with a reduced eruption risk in the Grindavík area due to the partial solidification of magma. Yet, the scenario remained dynamic, with a slight shift in activity by early December indicating possible new volcanic events. Despite a reduction in seismic activity and a slowing deformation rate, the situation remained precarious, with experts continuing to closely monitor magma movements up until the eruption on December 18, 2023.