Eruption at Meradalir, Iceland, Stalled 21st August 2022

Eruptive activity at the new fissure in Meradalir stalled on 21st August 2022 at around 6:00 am.  The seismic tremor ceased following the emission  of a blue grey plume.  Lava was seen on webcams to be still flowing from the crater just before then.  We await to see whether or not this is the end of this eruptive episode.

Fig 1:  Tremor plot for Fagradalsfjall.  Source: Tremor (

To quote IMO, “A new chapter is about to begin in the Fagradalsfjall fires, but whether the seismic activity will recur and it will erupt again in the near future or not, time will tell.”

What do we know of the eruption so far?  The eruption started on 3rd August 2022.  The initial discharge rate was c. 32 cubic metres per second, dwindling to 2 cubic metres per second by 16th August 2022. The total volume of lava emitted by 16th August 2022 was 12 million cubic metres, c. 8% of that emitted by the Geldingadalir eruption last year. At the crater the lava is 20 to 30 metres deep and 40 metres deep by the crater rims, themselves.  Over the rest of the lava field the lava is between 5 and 15 metres deep.  The new lava has displaced cooling older lava causing it to rise by 3 to 5 metres in places.

Fig 2: Lava fields 2021 and 2022.  Source: Eldgos í Meradölum | Jarðvísindastofnun – Institute of Earth Sciences (
Armchair Volcanologist

The lava composition is similar to the basalt emitted by Geldingadalir in September 2021. The K2O / TiO2 ratio ranges from 9.3 to 9.4 and the MgO is around 8.4 wt(%).

Armchair Volcanologist

© Copyright remains with the author; all rights reserved, 2022.

Sources: in the text