Volcano Eruption in Iceland

‘Volcano Eruption in Iceland’ Credits

Geldingadalsgos fissure eruption in March 2021.

Music: ‘Extinguished’ by Kai Engel is licensed under an Attribution License.

Following thousands of earthquakes and tremors near Fagradalsfjall in Iceland, a magma intrusion finally erupted through a fissure on Friday 19th March, 2021. Iceland’s newest volcano was dubbed ‘Geldingadalsgos’, after the valley in which it appeared. The valley itself translates to mean ‘castration valley’ or ‘Valley of the Eunuchs’.

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We had endured many sleepless nights in the lead-up, with countless earthquakes above magnitude 3.0 and several over magnitude 5.0. The tremors were so constant that we could feel them whenever we sat down.

Due to warnings by authorities, we began to prepare for an even bigger earthquake that could possibly be around magnitude 6.5.

When did the Seismic Swarm Begin?

The seismic swarm commenced in Fagradalsfjall on the 24th February 2021 with two large earthquakes, one measured at M5.7 and the other at M5.0. After that, thousands of earthquakes were recorded, with undulating intensity and frequency.

Scientists soon detected an expanding dike intrusion underground, with magma flowing into the corridor and increasing tremors within the area.

Geldingadalsgos Erupts

The volcanic eruption at Geldingadalir began at around 20:45 UTC on 19th March 2021, with a red glow being noticed in the clouds from nearby Reykjanesbær to Grindavík. It was considered to be a small eruption, with the fissure initially being estimated at between 500-700 metres in length. It was later measured to be around 200 metres in length.

The lava spread less than 1 km², covering an area approximately 500 metres wide. There was no ash and Keflavík airport remained open, though some roads in the vicinity of the eruption site were closed.

What is a fissure eruption?

A fissure eruption, also known as a fissure vent, volcanic fissure or eruption fissure, is a type of volcanic eruption that occurs through a vent. It is not usually associated with any explosive activity.

Corridors of rock, known as dikes, feed the fissure vents with magma reservoirs located beneath the earth.

In Iceland, fissure eruptions often occur where the Eurasian and North American lithospheric plates are diverging, in a system known as the Mid-Atlantic Ridge.

Possible developments following this eruption

The Scientific Advisory Board of the Icelandic Civil Protection met on the 20th March, to evaluate the latest developments of the volcanic eruption in Geldingadalir on the Reykjanes Peninsula. The conclusion of the meeting was that the following developments are possible:

- The eruption will decrease gradually and end in the coming days or weeks.
- New volcanic fissures could open at the eruption site or along the magma dike near to Mt. Fagradalsfjall.
- The likelihood of a large earthquake close to Mt. Fagradalsfjall has reduced due to the ongoing volcanic activity.
- An earthquake up to magnitude 6.5 could be triggered in the Brennisteinsfjöll volcanic system, located east of Mt. Fagradalsfjall.

Health and Safety

Lava flow from the eruption is not expected to have any immediate impact upon nearby towns or infrastructure.

Gas pollution from the eruption site is not expected to have a significant impact on the well-being and health of residents on the Reykjanes Peninsula and the capital area in the next few days. However, weather, wind direction and pollutants (such as sulphur dioxide and carbon dioxide) from the volcanic eruption can all affect the strength and distribution of the gas pollution.

For more information in relation to the volcano fissure eruption in Iceland, follow @Vedurstofan, the official account of the Icelandic Met Office on Twitter. You may also see the latest info on earthquakes and the eruption at the IMO website, which is updated regularly.

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