Massive lava cave opens up, results in lava flood down to Nátthagi

Yesterday (15-September-2021) around 11:10 UTC a large lava cave just south of the crater in Geldingadalir had a roof collapse in a small area or a lava breakup in the surface. This resulted in the lava flow down Geldingadalir into Nátthagi. The flow covered Geldingadalir in less than 20 minutes. After that it did reach the barrier that stops it from going into Nátthagakriki, if that happens both walking path A and B are going to get closed forever or having to be redrawn from their current locations. Lava down that path also allows the lava flow to go in the direction of Grindavík town and nearby roads.

The lava flow yesterday did go down into Nátthagi but didn’t get far into there compared with the older lava it was flowing on top of. This sudden lava flow did put people in danger and shows that the lava field is full of dangerous caves that can collapse or burst open at any time without any warning. The lava flow that started yesterday is ongoing best to my knowledge. But the view has been limited due to fog and bad weather in Fagradalsfjall mountain this evening.

One or two idiots where seen walking on the crater rim yesterday and I think this are the same people that Icelandic coast guard had to transport from Gónhóll since they where unable to get back because of the new lava flow that had happened when they where there.

The crater is now ~334 meters above sea level high. Currently the crater is now growing in height but that can change without warning.

Pictures of this new lava flow are on social media. I can’t use them because of copyright but if searched they can be found and viewed. There are also some amount of videos of this lava flow on YouTube.

Fagradalsfjall mountain is part of Krýsuvík-Trölladyngja volcano system.

Added 10-January-2022

This article can be found in Spanish here.

12 Replies to “Massive lava cave opens up, results in lava flood down to Nátthagi”

  1. Here’s a vid of what you are describing.

    I think a fissure opened under the lava field the other day, and lava is trying to find a way out. This is a very deep area of lava on this western side of Geldingadalir valley (60-80m or so), if folks remember the topo from the start.

  2. Would it be out of bounds to say that there is a bit of red-hot lava under there, and the fresh lava is able to reheat, and liquefy it, there-by creating channels? Definitely it’s moving through voids in the rock.

    1. Any area that has deeper lava than 10 meters is highly dangerous because of formations of lava ponds or lava caves in the area. That is all areas expect the rim of the lava field.

      Both lava ponds and lava caves can open up without warning at any time.

  3. The eruption in Fagradalsfjall mountain has now lasted longer than the eruption in Holuhraun (Bárðarbunga volcano). Holuhraun did last for 180 days. Fagradalsfjall mountain eruption has now lasted 181 day and is ongoing.

    1. Now that is some serious lava fountaining. Spraying rather high. Poor folks in the town nearby might lose everything. It’s pretty close.

  4. La Palma eruption going really strong. Uplift is continuing, so more vents are possible if this crater doesn’t enlarge first. Watching the eruption last night, lava fountains were running a good 500m above the crater with lava bombs that looked to be the size of cars being thrown up to 200-300 m away. Absolutely stunning video footage last night.
    Here’s live cam.

    They were prepared for this with evacuations that started prior to eruption of the elderly, and disabled. Unfortunately, major damage is going on, and will continue.

    Iceland eruption is sure small compared to this one.

  5. The eruption in Iceland did reach 6 months yesterday (19-September-2021). I made the chose on not writing about it.

    As for the eruption in La Palma, Canary islands, Spain. It seems to be about 10 times larger than the eruption in Fagradalsfjalli mountain.

  6. Fagradalsfjalli eruption may come back soon. Tremors are indicating life down there. Plot looks like it did before this last eruption.

    Wonder which Icelandic volcano is next. The Atlantic basin running hot this year. Iceland, Canaries, and lesser Antilles have been busy. NEXT!!

  7. Drone video graphics indicates the inner crater has collapsed inwards creating a barrier.

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