Lava flow during a volcanic eruption near Litli Hrutur, southwest of Reykjavik, Iceland, on July 10, 2023. The peninsula near the capital has seen major volcanic activity in recent years, resulting in a significant influx of tourists in led the country. | KRISTINN MAGNUSSON/AFP/METSUL METEROOLOGIA
Iceland is on alert for an impending volcanic eruption, preceded by a large wave of earthquakes near the capital Reykjavik. Some of the strongest tremors were felt in the capital this Friday, further raising the alert level of Icelandic authorities who fear a larger eruption than in recent years.
This impressive video comes from #GrindavikThe main point is the intense seismic sequence in the Corso or Islanda in question. I started to leave sleep quickly but couldn’t establish myself in the act. Read the Vengono Avvertite practically in continuous mode. pic.twitter.com/EYx0RCUWpG
— Il Mondo dei Terremoti (@mondoterremoti) November 10, 2023
A wave of hundreds of earthquakes, including two with a magnitude greater than 5.0 and at least seven with a magnitude of 4.5, shook Iceland’s Reykjanes peninsula near the capital on Friday. The socalled “seismic swarm” suggests a local volcano will erupt in the coming hours or days and has prompted the Icelandic Meteorological Office to declare a state of emergency.
The Fagradalsfjall volcano is located in the southern region of the Icelandic peninsula, about 40 kilometers southwest of Reykjavik, the country’s capital. Several tremors shook the city and the famous Blue Lagoon geothermal spa in Grindavik was closed. It was initially unclear whether Fagradalsfjall was responsible for the increased seismic activity or whether an eruption was occurring elsewhere in the Reykjanes volcanic system.
Shortly before midnight local time, the entire population of Grindavik was warned to leave the city. The weather service warned that volcanic fissures could open near or within the city. “Based on the development of seismic activity since 6 p.m. today and the results of GPS measurements, there is a probability that a magma intrusion has extended to beneath Grindavík,” the office wrote.
Experts believe that a magmatic vein has formed directly beneath the city. Dikes are layers of magma that flow through existing cracks in the rock or create a new fissure. The largest volcanoes can contain hundreds of dams.
A code orange or level 3 out of 4 on the universal warning scale for terrestrial volcanoes has been declared, causing concern at Keflavik International Airport, which lies northwest of the seismically active region.
There have been repeated outbreaks in the region since 2021, but the outbreak, which could start at any time, is likely to be more severe. “The amount of magma involved is significantly larger than that observed in the largest magma intrusions associated with eruptions at Fagradalsfjall,” officials said.
The government warned on Friday afternoon that the earthquakes occurred about three kilometers northeast of Grindavik and the faults occurred about three to three kilometers underground. The earthquakes shook the community of 3,300 people around sunset.
Emergency Management Department @almannavarnir has decided to place an order #Evacuation from #Grindavik given the uncertainty where #Eruption will happen. All citizens must leave the area immediately. Information about the evacuation plan can be found at https://t.co/zB7y1wjHiw #reykjanes pic.twitter.com/AxN69rEXQa
— Gisli Olafsson (@gislio) November 10, 2023
“Seismic activity has shifted south towards Grindavík,” the weather service said. “The signs now seen… are similar to those observed on the eve of the first eruption at Fagradalsfjall in 2021 and are very similar to seismic activity measured approximately a month before this eruption,” the office warned in a previous update.
Previously, it was estimated that it would take several days for the magma to reach the surface and the impending eruption to begin. The quake has already destroyed roads. There was up to seven centimeters of uplift or vertical movement of the ground near the volcano.
There have been over a thousand earthquakes on Iceland’s Reykjanes Peninsula in the last 24 hours alone, caused by rising magma. Even roads are starting to break up. The town of Grindavík is under an evacuation order as fears of a volcanic eruption grow. pic.twitter.com/WkWxTwemrW
Collin Gross (@CollinGrossWx) November 11, 2023
Although Iceland is tectonically and volcanically active, the region around Fagradalsfjall volcano remained inactive for more than 6,300 years, until December 2019. At that time, a series of earthquakes, including two with a magnitude of 5.6, shook the peninsula. Then, on February 4, 2021, a magnitude 5.7 earthquake caused minor damage to homes. Six weeks later, on March 19, the volcano erupted, spewing lava through a fissure about 600 meters long.
The fissure was later named Geldingadalsgos and represented a possible new shield volcano a wide volcano with gently sloping sides and attracted widespread tourism. Several more columns opened in April, but only one remained active as of May 2021.
On August 3, 2022, another fissure eruption occurred outside Fagradalsfjall. Last summer, in early July, a new eruption began near LitliHrutur, also part of the Fagradalsfjall volcano. The eruption was about ten times larger than the first two eruptions and subsided on August 5th.