What do we know about the December 2023 eruption near Grindavík, Iceland?

Reykjanes eruption Iceland eruption

An eruption began on Iceland’s Reykjanes peninsula on December 18, 2023 at 10:17 PM. As of the morning of December 21, there was no visible activity at the eruption site, and the eruption has now been declared officially over. The eruption site is near Sýlingafell mountain, some 3km [1.9mi] away from the town of Grindavík. It did not impact air traffic or threaten infrastructure.

The Department of Civil Protection declared an emergency phase due to the eruption. Roads to Grindavík are closed to the public and authorities asked civilians to stay away from the eruption for their own safety and the safety of others.


More powerful than recent eruptions in Iceland

The December eruption was the fourth in three years on the Reykjanes peninsula. It began much more powerfully than the previous three eruptions in the same area, however. The eruption produced more lava in its first seven hours than all of the lava produced by the Litli-Hrútur eruption earlier this year.

The Sýlingafell eruption is a fissure eruption, with the southern end of the fissure some 3km [1.9mi] northeast of Grindavík, whose 3,600 residents have been evacuated since November 10. The eruptive fissure is nearly 4km [2.5mi] long, with the northeast end just east of Stóra-Skógfell mountain. Lava did not flow in the direction of Grindavík, and the flow weakened rapidly once the eruption had begun and did not impact any infrastructure. The map below shows the location of the eruption fissure in relation to Grindavík, the Blue Lagoon, and Svartsengi Power Plant.

Reykjanes eruption Iceland eruption
Icelandic Met Office. The approximate location of the eruption fissure in relation to Grindavík, the Blue Lagoon, and Svartsengi Power Station


Iceland eruption preceded by earthquake swarm

The eruption was preceded by an earthquake swarm that began around 9:00 PM, just over an hour before lava broke the surface. For more on the seismic events that preceded the eruption, read this article.



In addition to following our news coverage on the earthquakes and eruptions on Reykjanes, readers may find the following resources useful:

The Icelandic Met Office

SafeTravel, for travel warnings and tips for staying safe.

The Icelandic Road Administration and its live map of road closures throughout Iceland.

The Department of Civil Protection and Emergency Management.

Iceland Review magazine published a photo series on the evacuation of Grindavík.

This article will be updated regularly.

Blue Lagoon to Remain Closed Until November 30

The Blue Lagoon Iceland

The Blue Lagoon, along with its associated facilities, has extended its closure until November 30 due to ongoing geological unrest on the Reykjanes peninsula. Following the detection of sulphur dioxide emissions, an immediate evacuation of Grindavík was ordered earlier today.

Closure extended

Last Thursday, November 9, the Blue Lagoon announced that it would be closing its lagoon, hotels, spa, and restaurants owing to the ongoing geological unrest in the area. The closure was initially slated to last until November 16, at least, with the situation being regularly assessed.

Tonight, given that the geological unrest has continued, the Blue Lagoon announced that it would be extending its closure until November 30. As noted in the announcement, it is currently impossible to determine when or where a volcanic eruption might occur. The Icelandic MET Office, the Department of Civil Protection and Emergency Management, alongside a team of scientists from the University of Iceland are closely monitoring the situation and analysing ongoing developments.

Immediate evacuation ordered

Earlier today, residents of Grindavík were allowed a brief return to the town to collect valuables. Shortly before 3 PM, while around 90 residents were in their homes and businesses, the Department of Civil Protection and Emergency Management, in conjunction with the Suðurnes Police, mandated an immediate evacuation, signalled by town sirens.

The authorities later clarified that the rapid evacuation of Grindavík was prompted by readings from the Icelandic Meteorological Office’s gas metres, which detected sulphur dioxide emissions from the ground near Grindavík. The Suðurnes Police reported that the evacuation was completed in just 95 seconds. Officials express hope that they can allow residents to safely return to Grindavík tomorrow.

Full statement

Below you will find the full statement from the Blue Lagoon:

“The chances of a volcanic eruption on the Reykjanes Peninsula have significantly increased, initiating the precautionary evacuation of the town Grindavík to ensure the safety of residents. The evacuation commenced on the evening of November 10, following a Phase of Emergency declared by the Department of Civil Protection and Emergency Management.

At this moment it is not possible to determine when or where an eruption might occur. The Icelandic Meteorological Office, Civil Protection, and a team of scientists from the University of Iceland are closely monitoring the situation and analysing the developments.

Iceland is no stranger to volcanic activity, and there have been three eruptions on the Reykjanes Peninsula in the last two years. Icelandic authorities and local communities are well-prepared for such events, and Iceland has one of the world’s most effective volcanic preparedness measures. Iceland’s geoscientists possess vast experience in dealing with volcanic activities.

On November 9, Blue Lagoon made the proactive decision to temporarily close its facilities, affecting operations at Blue Lagoon, Silica Hotel, Retreat Spa, Retreat Hotel, Lava, and Moss Restaurant. Considering disruptions to our guests’ experience and the sustained pressure on our employees, these precautionary measures were taken to ensure the safety and well-being of all. The closure will remain in effect until 7 AM on November 30, at which point the situation will be reassessed.”