Update on the eruption in Fagradalsfjall mountain on 30-April-2021

This is a short update on the eruption in Fagradalsfjall mountain on 30-April-2021.

There has not been any major changes since last update. This are the noticeable changes since last update in the eruption in Krýsuvík-Trölladyngja volcano system.

  • Just one crater is now erupting. All other craters have stopped erupting but for now some of them might contain lava lake for now that might be creating a flow in lava tubes under the surface in the lava field. This process might not be visible on the surface.
  • A lot of activity now is in form of high lava arcs (correct word?) are now being formed in the one crater because of increased gas content of the lava.
  • Lava fields are slowly filling up all nearby valleys that it is flowing into. This is a slow process and is going to take months.
  • There are no signs the eruption is about to end.

No other updates have been reported so far. Rúv has installed a new web camera to give better view of the eruption. That camera can be found on YouTube Rúv channel.


I am going on a small vacation between 5th May and 10th May. That means next update about the eruption is going to be on 14th May. I don’t know if I can go to the eruption yet as that depends on the weather and the weather is always unstable in Iceland.

Earthquake swarm in Hengill volcano

Sorry for the late article. I’ve been dealing with technical problems in my mobile phone all day and delayed a lot of things for me.

Yesterday (29-April-2021) an earthquake swarm started in Hengill volcano. This earthquake swarm appears to be tectonic in nature. Largest earthquake in this swarm had a magnitude of Mw3,8 and was felt in Reykjavík.

Far left on image is a green star that shows the earthquake activity in Hengill volcano
Earthquake swarm in Hengill volcano. Copyright of this image belongs to Icelandic Met Office.

This earthquake activity looks tectonic in nature and there are no signs that the reason for this earthquake swarm is anything but tectonic stress adjustments for now. I always expect more and stronger earthquakes swarm when cold volcanoes (not erupted for a long time) starts to get warm as was the case before the eruption in Fagradalsfjall mountain when up to 50.000 earthquakes took place from 27th February until 19th March when the eruption started.