Update on the eruption in Sundhnúkagígar on 19. December 2023 at 21:46 UTC

This is a short update and information here might go outdated quickly. This article is written on 19. December 2023 at 21:46 UTC.

I am trying to collect and read all the information I can find. I don’t have access to everything my self, so I am depended on news and reports from Icelandic Met Office and others on what is happening in this eruptions. This is not unusual and has always been like this.

  • The eruption is now in 2 to 4 vents. I am little unclear at the writing of this article now many are erupting.
  • The new dyke seems to go into the dyke from 10. November. This can result in reactivation of the dyke from 10. November and result in an eruption along it, all 15 km at random location.
  • Current flow seems be around 50m3/sec at the writing of this article. I’ve been hearing that highest flow yesterday (18. December) was around 800m3/sec, but that number is for me unconfirmed. It dropped to 100 – 500m3/sec soon after the eruption started.
  • Early GPS data from today seems to suggest that Svartsengi volcano has lowered about 50mm since the start of the eruption. I am waiting for new GPS data on Icelandic Met Office website. That data hopefully shows up tomorrow (20. December).

There’s a lot of uncertain things that can happen with this eruption at the moment. Since there’s a lot of lava in Svartsengi volcano that has not erupted so far. New inflow of lava from the deep mantle is also a possibility and those can happen without warning as the pressure drops in Svartsengi volcano sill (or magma chamber).

I’ll post next update tomorrow (20. December 2023) or sooner if anything happens.

Update on the eruption at Sundhnúkagíga on 19. December 2023 at 16:10 UTC

This article is short and is written at 16:10 UTC on 19. December 2023. Information here can go outdated quickly and without warning.

There has been a reduction in the eruption since it started at 22:17 UTC on 18. December 2023. This was to be expected. Since the eruption seems to be coming from a small sill in Svartsengi volcano, rather than a large magma chamber.

  • The eruption is now limited to three to four eruption vents. The largest one is where the eruption started. Crater building is ongoing.
  • The lava is flowing towards Fagradalsfjall volcano (mountain) at the writing of this article. This area is empty, outside of the the parking lots south of Fagradalsfjall. They are not at risk for now.
  • The problem with eruptions of this type is that they can grow again in size if different sill breaks and starts flowing into the established flow channels that magma is now flowing and creating the eruption. If that happens is impossible to know. This can also result in a eruption that goes on for a long time. If that happens, an lava might end up reaching far away areas.
  • It is going to take few days for GPS data to show what sill is deflating in Svartsengi volcano and what is going on in the crust in Svartsengi volcano.
  • Weather might be a problem for next few days on Reykjanes peninsula.
  • This area is not to hike around on. Its dangerous and the weather makes difficult walk extremely difficult.  Just watch the online web cameras.
  • The lava field is large and it creates its own strong wind as the lava warms up the air around it. That can be difficult to deal with in the snow for anyone close the the eruption.

The dyke is longer than the part that erupted according to the news and measurements. The dyke is more south and it ends just 1,5 km north of Grindavík town. That area can erupt without warning if pressure starts to build up in that part of the dyke. That same goes for the north part of the dyke, how far more north the dyke is I don’t know.

I’ll post next update when I have more information what is going on or sooner if anything happens.

Update on the eruption in Sundhnúkagíga on 19. December 2023

This article is written on 19. December 2023 at 02:35 UTC. Information in this article can go outdated quickly and without warning.

  • The fissure is at last measurement around 4000 meters long (4 km) according to the news.
  • The volcano that is erupting is Svartsengi volcano. On some maps this is shown as Reykjanes volcano.
  • This is the largest eruption on the Reykjanes peninsula  so far.
  • The lava flow is mostly to the east, a way from infrastructure and roads. This is mostly, but can change without warning.
  • There’s a lot of gas pollution from this eruption. This gas is dangerous to people and animals.
  • The lava flow from the fissure is around 100m3/sec to 200m3/sec.
  • The fissure has started to form crates. This is going to continue to create craters as the eruption goes on.
  • There’s a ongoing risk that the eruption fissure might extend to the south towards Grindavík. If that actually happens is impossible to know.

I am going to write next update sometimes later today (19. December 2023) when I have new information and more is known about this eruption.