Not wishing to be alarmist about Katla, which I’ve been following for several months, I do wonder if a pattern in the (minor) earthquakes currently is in any way significant.
The thumbnail image above is from Erik Klemetti’s blog post Small jokulhlaup at Katla in Iceland. [Update 20th July below] He also recommends this flyover of Katla by helicopter showing both the ‘caldera’ depressions in the glacial cap and the effects of the jokulhlaup (glacial outburst flood).
There’s been a bit of hype (probably too much). Although Katla will go sometime, it still could be a long way off. However, when I checked yesterday there was a regularity to the quakes – a quake or small swarm every 6-7 hours. This is still continuing today.
I am no expert but this makes me wonder of magma is pushing up and the strain ‘gives’ regularly.
Update 20th July: from Jón Frímann’s Iceland Volcano and Earthquake blog (19th July)
According to the news here in Iceland there have been a formation of at least three new cauldrons in Mýrdalsjökull glacier, where they have not been before in the glacier. But this means that the hydrothermal areas under the glacier are growing in size due to new magma pushing up into the crust and warming it up.
Read the rest here: New cauldrons forms in Mýrdalsjökull glacier (Katla volcano)