Yesterday (10-December-2015) a earthquake swarm started in south-west Langjökull (Prestahnúkur volcano [Wikipedia page here]). Currently the earthquake swarm is ongoing. This is a slow earthquake swarm so far, not creating many earthquake over period of one hour. Largest earthquake so far had the magnitude of 3,2. Other earthquakes have been smaller, but many earthquakes are over 2,5 in magnitude. The largest earthquake was felt in nearby town of Hvanneyri and possibly other farms close to the location where the earthquake swarm is taking place.
The earthquake swarm in south Langjökull volcano (Prestahnúkur). The earthquake swarm is located in one spot. Copyright of this image belongs to Iceland Met Office.
This earthquake activity is appearing on my geophones when it comes to earthquakes over magnitude 1,9. Every 10 to 20 years this area has earthquake swarms that creates earthquakes with magnitude 4,0 and above. Last such earthquake swarm was something over 10 years ago if my memory is correct. At the moment there is nothing suggesting that eruption might happen at this volcano any time soon. Last eruption took place 3500BCE (GVP information).
Thanks for the article Jon.
I still would like to ask, do you think this activity is tectonic or volcanic?
This activity looks tectonic at the moment. Based on the pattern I’m seeing on my geophone it appears to be a rift valley formation earthquakes.
Thank you Jon
So this activity is probably related to the Rift that runs through Iceland, does this look like the rift is moving in a more northerly direction or is it just an indication of the on going rifting process ? Would you say this activity is a result of a release in the rift or a result of the pressure building for a greater rift movement yet to come?
It’s starting again…
Yes, one more green star to come.
Friday
11.12.2015 22:06:25 64.616 -20.630 2.0 km 2.9 99.0 14.7 km SE of Húsafell
Saturday
12.12.2015 04:38:24 64.612 -20.633 1.9 km 3.4 99.0 14.9 km SE of Húsafell
Friday
11.12.2015 22:37:48 64.607 -20.624 1.3 km 3.0 99.0 15.6 km SE of Húsafell http://en.vedur.is/earthquakes-and-volcanism/earthquakes/langjokull/#view=map
Still tectonic in nature?
Yes, so far and the earthquake swarm has been slow after a sharp peak last night. That pattern might repeat for the next few days to weeks.
Thanks Jon.
Yes. I would also like to say thanks Jon.
And thanks for the readings Luisport.
Thank’s! 😀
I’m going to post an update about this earthquake swarm tomorrow. I’ve been watching and it is clear that it’s not over.
Earthquake activity in Grímsfjall volcano is also slightly higher than background activity. Nothing worth writing about yet, but worth watching for now.