Hi

>From December, when I got the geophone I have been seeing long period
events on it. Those events can last up to 6 min, and have a constant
energy around 10 - 12Hz (can go up to around 20Hz). Until today I was
unsure for the reason of this noise, until today. Last night at 01:49
there was a small earthquake at the distance of 63km away from my
location, the size of this earthquake was 1.94M, at 17:31 today there
was a second small earthquake at the distance of 62km, the size of that
earthquake was 2.1ML according to IMO automatic systems. But following
that second quake I did see something unexpected, a long perid event,
lasting up to 4 - 5 min, with energy from 10 - 13Hz, the event start was
few seconds after the small earthquake that did happen near Northen
Langjökull Volcano, but both of thease earthquakes are in it's fissure
swarm. But also in this earthquake there is alot of energy around 5Hz,
not part of the earthquake it self (looks like that). Depth of those two
earthquakes is from 3.6km to 2km.

I am unsure if those long period events are volcano related or not.
Input on this might help me figureing this out. Also, I can email the
event files to those who want them.

Regards.
-- 
Jón Frímann
http://www.jonfr.com
http://www.simnet.is/jonfr500/earthquake/

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