An update on the Icelandic volcano at Katla

I have been monitoring the earthquakes about the Katla volvanic site in Iceland, since the eruption at the adjacent Eyjafyallajokull volcano last year. This was initially based on the historic pattern where an eruption at Katla has followed the Eyjafyallajokull eruption some eighteen months later. So I monitored the earthquakes to see if patterns could be found, and I used the info on the quakes that is posted by the Icelandic Met Office, I started by listing the earthquakes larger than magnitude 3, ( here ) thinking that this might provide some precursors to the eruption.

But I was also monitoring the location of all the earthquakes in the Katla region. As I did so I noticed that the initially rather random pattern of these quakes was beginning to focus around a number of different spots. Since there are about half-a-dozen of these quakes a day the plots can lose clarity after a while, and so last month I started putting the quakes into ten-day segments of different colors. This month I am going to try putting them on different layers in Photoshop as well, so that I can separate out the different phases and carry them forward as a running total. So this is the pattern for June.

Volcanic activity at the Katla volcano site in Iceland in June 2011. Red were in the first ten days, green in the second, and blue in the final eleven days of the month. Katla lies under the glacier Myrdalsjokull. (info from Icelandic Met Office)

You will notice that the “focusing” of the quake activity has continued to reduce the overall area in which they are occurring. In addition over at the Iceland Volcano and Earthquake blog reports are appearing of harmonic signal development possibly suggesting the movement of magma under Katla.

I’ll continue to post these at intermittent intervals until there is an eruption, or the focus dissipates.