Here is a picture of a earthquake that took place in Askja volcano last night. This earthquake was bearly visable on my geophone close to Hekla volcano. From this data it is clear that the earthquakes are created by magma movements inside Askja volcano. But the earthquake swarm is taking place on the edge of Askja volcano main system. It is not happening outside as it might appear.
It is also worth pointing out that not all of Askja volcano earthquakes might appear on the automatic SIL system. But most of them should do so. As Askja volcano is remote and in a unpopulated area there should not be any damage from a eruption. The only damage might happen if there is a eruption in Askja caldera lake due to ash cloud that might form.
Askja volcano earthquake. This is low pass filtered at 1Hz. This image is released under Creative Commons License, see top link for more information. Click on this picture for full resolution.
This earthquake has magma signature from the looks of the earthquake signal. But due to distance it is hard to be sure on that.
When this is written a tremor pulse appears to be starting in Askja volcano. But this might also be a swarm of micro earthquakes taking place in Askja volcano without the earthquakes appearing on the automatic SIL system. At this point it is hard to know for sure, as this activity is new.
Locations of the earthquakes in relations to the Askja volcano system. As can be seen on this map from Icelandic Met Office, the earthquakes are clearly inside Askja volcano. Even if they are not at the main caldera. Picture is from Icelandic Met Office web site. Copyright of this picture belongs to Icelandic Met Office.
Blog post updated at 16:37 UTC on 5 May 2011. Picture is added.
Nice update, thank you. How many times has this sort of activity happened since the last eruption(s)?
I see the following on the wikip page:
“In June 2010, Volcano expert Hazel Rymer said seismic activity was increasing at Askja and that an eruption could be around the corner[2] The increased earthquake activity is located to the northeast of the central volcano, in the direction of Herðubreið. It was ruled out that any activity from Eyjafjallajokull was responsible for the increase in activity at Askja. The news came as scientists continue to watch Katla.”
Over the past few years Askja volcano has not been this active far as I know for a long time.
I have not seen this type of shallow activity before in Askja volcano.
More shallow earthquakes close to Askja. And, tremors have started to rise, see http://hraun.vedur.is/ja/oroi/ask.gif Does this imply an eruption is imminent? Nobody knows for sure, but time will tell…
Tremor changes are due to more wind in the area. A volcanic tremor goes way above the background and the wind noise normally seen on the tremor plots.
Comparing the various frequency bands in http://hraun.vedur.is/ja/oroi/ask.gif
Blue line is not affected very much, but green and red lines are rising slowly, so I suspect this is not only wind. If you check dates 26.4.-30.4. all lines were siginificantly affected due to heavy winds.
Anyway, I’m NOT a volcanologist/geologist/etc. but just a physicist interested in volcanoes — who also happens to like simple explanations!
2 new quakes.. at shallow depth. Quite some quakes today in the area northeast of Askja.. Also stronger than yesterday!
Seeing some LF spikes in the latest tremors… getting more interesting!
Mike
Two of the low frequency spikes are earthquakes in Alaska with the size Mb6.0 and earthquake in Japan, with the size Mb6.3.
I just want to point out also that globally, the last several weeks have seen a very sharp rise in the # of medium to large quakes (4-6 range). Specifically, the pacific plate off mexico, alaska/northern calif.
I would not be surprised at all to see a large event in Southern Calif-Mexico or Alaska-Cascadia zone
Well it is interesting to see Askja awakening, I have a small piece of this volcano at my desk 🙂 A friend of mine had brought it (who was hiking there some years ago). So this seems to be a bit personal to me. Jón, thank you for the updates!
I have pieces of volcano rock from Azores, Canary Islands, and Cape Verdes from our last cruise..sure hope THOSE don’t become keepsakes of eruptions. Interesting to watch the seismic activity, and graphs. Do not claim expertise, sure good to have this site, Jon!
I’ve also got bits of volcano – from Mount Etna. We climbed up it whilst it was smoking on the top (the very top part was out of limits for obvious reasons) and I remember the ground being so hot it nearly melted my footwear. Exciting stuff!
I hope that Askja volcano doesn’t start erupting until I have moved back to Iceland.
I wouldn’t actually bet on it.
Maybe Askja is not going to erupt at all (in soon), and tomorrow we wake up with an eruption in Hekla, Grimsvotn or Krisuvík. 😉
Could be interesting if it is as rapidly building as it appears to be..
Going back to the Homeland ? Jon? been there done that when I was
a young man. …
Is the Godabunga Tremor looking completely normal?
To my eyes, most likely yes (weather effects included).
I wonder if the earthquake activity in Askja volcano is changing. It has been quiet over the last few hours.
Now we have a few quakes at the other end of Askja, in the South… something moving a little to take up the strain? Wish we had better deformation data…
Mike
Low-frequency tremor is increasing steadily but high-frequency tremor (wind) is steady, so something is definitely cooking there…
Looking at the Askja tremor plot, I’m not sure how to interpret it. The red band (low freq) is slightly increasing but isn’t the amplitude also important?
It is just weather in Iceland. A volcano activity in the tremor plots is clear when it happens, as it goes above the weather background noise.