Iceland volcano: Blue Lagoon closes over eruption fears

The increased activity is concentrated around the Fagradalsfjall volcanic area in the southwest of the country

Thousands of minor earthquakes have raised fears in Iceland of an possible volcanic eruption.

Over 20,000 tremors have been detected by the Icelandic Met Office (IMO) since late October, with 1,400 in the 24 hours to midday on Thursday.

The heightened geological activity led to the famed Blue Lagoon being closed as a precaution.

It is concentrated in the southwestern Reykjanes Peninsula, which was dormant for 800 years before a 2021 eruption.

The IMO said that magma - molten rock - was accumulating at a depth of around 5km (3m) northwest of Thorbjorn mountain.

The Blue Lagoon is easily visible from the mountain. The owners of the famed turquoise hot springs said they would close the site until 16 November out of concern for employees' welfare.

The Met Office said an earthquake of 5.0 magnitude, the largest since the increased activity began, was detected shortly past midnight on Thursday in the Fagradalsfjall volcanic area, around 30km from the capital Reykjavik.

Ingibjorg Lilja Omarsdottir of the Icelandic Civil Protection Agency has been posted to the nearby town of Grindavik to prepare for a potential evacuation of the town.

She said there was no imminent need for evacuation but that local authorities were prepared in the event of "magma appearing to rise to the surface".

Volcanic eruptions occur when magma, which is lighter than the solid rock around it, rises to the earth's surface from deep below it.

This Met Office graphic shows the swarm of tremors felt in the past 48 hours on the Reykjanes peninsula

The town would have around "a day and a half" notice in the event of an imminent eruption, Ingibjorg Lilja told the BBC.

She stressed that there was no risk of another massive explosion comparable to the eruption of Eyjafjallajokull in 2010, which shut down northern European airspace for days.

Iceland is one of the most geographically active regions in the world.

The island nation counts around 30 active volcanic sites.

In July, Litli-Hrutur, or Little Ram, erupted in the Fagradalsfjall area, drawing tourists to the site of the "world's newest baby volcano".

The site was dormant for eight centuries until eruptions in 2021, 2022 and 2023.