Sunday, May 22, 2011

An Icelandic volcanic eruption

Well this is interesting. I wrote a week ago about the pattern of earthquakes that was developing in the Mydralsjokull area of Iceland. However, earlier this year there was a growing pattern of earthquakes around the Grimsfjall region in Iceland, which is also known as the Loki volcano, There has now been an eruption in that region. And while the power of the volcano is already waning somewhat, there is some anticipation that the overall eruption might be larger than the Eyjafyallajokull eruption that happened last year, and the largest eruption at this site in over 100 years. At present the ash particles are being reported as larger than that from last year’s eruption, so that it likely won’t be as disruptive. It is also being blown northwest, and so does not threaten the main air corridors at the moment.

What makes it more interesting, and a little worrisome, however, is the line of strong earthquakes (i.e. above a level 3) that are shown by stars in the map below, and which run down from the current eruption towards Mydralsjokull, which is at the bottom. And these all happened in the last day. For convenience I have given the volcanoes their Norse names of Loki (which is where the current eruption is), Laki, which is the volcano that erupts along the line of the green stars, and Katla, which is the volcano at Myrdallsjokull. The largest of the earthquakes is a 4.6 and is down near Laki, rather than in the Loki region.

Recent earthquake activity in Iceland (Icelandic Met Office)

The recent low level of activity on the island (there hasn’t been a magnitude 3 since March, when usually there is one about every three days) suggests that there may be some energy to be relieved, and this might open one of the fissures at Laki. These are the big volcanoes which do bad things to air quality, not only in Iceland, but also often in Europe. We will have to see how this goes.

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