Category: Sundhnúkagígar

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Update for Grindavík on Monday, 20. November 2023

This is a short update on the situation in Grindavík. This article is written on 20. November 2023 at 22:22 UTC.

Storm warning

There’s a storm in Iceland until 23. November 2023. When the wind is going to start die down again. This means that Icelandic Met Office is going to record fewer earthquakes because strong ocean waves and wind.

Daily update

  • There has not been much change since yesterday. This is normal.
  • Inflation in Svartsengi is up to 30mm/day and this is a increase, since inflation used to be around 15mm/day.
  • Since Friday 10. November 2023 the inflation in Svartsengi has been around 150mm over the last 11 day time period.
  • It took 17 days from start on October 25 of the magma inflow into the Svartsengi dyke until it broke on 10. November and the created the Sundhnúkar to Grindavík dyke.
  • It is a question what happens when next 17 days come up. Because whatever the hold is for the magma in the dyke in Svartsengi is going to break it is going to start the process as happened on 10. November 2023 and possibly into the current dyke, or possibly create a new dyke next to the current one (its a possibility, not a large one, but it is there).

Other updates

There has not been a lot of information released today and I don’t see a lot on seismometers and other instruments around Grindavík town currently.

This is a image of the danger zone around Grindavík and north of it. Its divided into three zones. With the colours orange, red, purple.
The current danger zone map from Icelandic Met Office. Zone A (orange) is the least dangerous area. Zone B (Red) is a dangerous zone, risk of fissures opening up, erupting crates, lava flows and gas pollution. Zone C (purple) is the most dangerous zone, Its close to same as zone b, but increased risk of dangerous volcano gases and entering it requires wearing a gas mask, have a gas and have gas measurement tool when going into the zone. Red dotted line is the estimated location of the dyke. This map also shows fissures in this area and the rift valley. Copyright of this image belongs to Icelandic Met Office.

This type of quiet period before an eruption are common. Why is not well understood. Eruption might not happen, but it is not likely that nothing is going to happen in this. Both is magma too close too the surface and there’s too much inflow of magma into the dyke at Svartsengi. This is how I see the current situation.

If anything happens. I’ll post update soon as I can.

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Update on Grindavík 17. November 2023

This is a short update on the situation in Grindavík on 17. November 2023. Information here can go outdated quickly and without warning.

Daily updates

  • Grindavík town continues to sink as the rift valley continues to move. The speed of sinking has slowed a little according to the news today.
  • Earthquake activity has slowed down in last few hours (this is written around 22:51 UTC). What that means is unclear.
  • Some houses in Grindavík town have been completely destroyed. Iceland has a natural disaster fund for this type of situation and that is going to cover the owners loss according to the news.

General update

It took me a week. But it seems that this dyke intrusion under Grindavík town is because of the magma sill (dyke) under Svartsengi. That area has inflated around 110mm in a week. That is a inflation of 15mm/day based on my best calculations. That is a lot of inflation, since before 10. November the inflow of magma into Svartsengi was at most 8m3/sec according to measurements of Icelandic Met Office.

The sill in Svartsengi created a lateral dyke in Sundhnúkar and nearby areas. When the pressure in the sill is high enough again it is going to push the magma into the dyke at Sundhnúkar again with the same force as it did before. How long that takes I don’t know. Last time this was from 25. October to 10. November. That’s seventeen days, but there was a lot of deeper sills in Svartsengi and its impossible to know much, if anything flowed form them into the dyke. This is my personal view, it might be wrong. But this is what I am reading from the data.

Risk of the eruption remains high because there’s a ongoing inflation at Svartsengi. When a eruption starts is impossible to know.

If anything happens. I’ll post update soon as I can.