When this is written around 00:36 UTC on 9. July 2011 the harmonic tremor levels on SIL stations around Katla volcano have continued to increase. The latest spike in harmonic tremor levels happened after an ML1.5 (automatic size) earthquake that took place at 22:13 UTC. There has been an small earthquake swarm in Katla volcano caldera yesterday. But the largest earthquake in that earthquake swarm had the size ML2.4.
The harmonic levels are getting so strong that they have started to appear on stations around Hekla and on my own geophone, even if it is located almost 60 km away from the source of the harmonic tremor. Currently there is little to suggests that this is slowing down at the moment. But that might yet happen. But it is impossible to know for sure at the moment.
The lack of earthquakes tells me that the magma has not yet reached the surface. When or if that might happen is an good question that I do not have the answer to. But this might take several more hours until something happens in terms of earthquakes or other activity in Katla volcano.
As sad before the harmonic tremor can now be seen on SIL stations far away from Katla volcano. But the maximum range so far is around 65 km or so at the moment.
This is the last update for tonight. I am going post an update tomorrow on what has happened during the night. Even just to say people that things have slowed down or gone back to normal. Whatever happens. I am going to post information about it tomorrow when I awake up.