Here are few images of the last earthquakes in the large earthquake swarm that took place in Katla volcano 28 – 30-September-2016. The alert status for Katla volcano has been downgraded from Yellow to Green.
Earthquake information from Heklubyggð geophone
I was only able to record few earthquakes from the swarm in Katla volcano. Along with the largest earthquakes that happened. Most of the earthquakes where hybrid earthquakes or Volcano tectonic earthquakes, few low frequency earthquakes took place, but I recorded them really poorly due to weather and strong wind at the time in south Iceland. More information about earthquake volcano types can be found here (USGS) and here (alaska.edu). There are no P and S wave markers in this images. I didn’t have the time to process this earthquakes properly yet.
The first earthquake appears to be hybrid earthquake. The second earthquake appears to be a volcano tectonic earthquake. This image is under Creative Commons Licence, please see CC Licence page for more details.
The first earthquake appears to be volcano tectonic earthquake, the second earthquake appears to be two earthquakes happening at once. Making analyse of what type this is difficult. The last earthquake appears to be a hybrid earthquake. This image is under Creative Commons Licence, please see CC Licence page for more details.
The largest earthquakes all appear to be volcano tectonic earthquakes. Other earthquakes where difficult to record due to high wind noise at that time.
I finally found the GPS information website for Katla volcano. There isn’t much change on most of GPS station around and on Katla volcano. The most change is happening in Austmannsbunga (AUST) inside the caldera. Other GPS stations do now show this change, suggesting that it might be highly localised change not appearing on other GPS station for now. This doesn’t look like a error or a fault in the measurements. The GPS website for Katla volcano can be found here.