Day: October 9, 2010

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The harmonic tremors of a volcanic eruption

Many people want to know how to identify a volcanic tremor when they appear. Here are few examples of volcanic tremors that I have seen over the past few years.


The volcanic tremor following the eruption in Grímsfjall in 2004.


Harmonic tremor spike in 2005, following a glacier flood in Skaptárkötlum in Vatnajökull glacier (they are in Hamarinn volcano).

I hope that this two examples show people what to look for when something is going on in Icelandic volcanoes. All images are from Icelandic Met Office web page.

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Sudden rise in harmonic tremors around Katla and Eyjafjallajökull

There is a sudden and sharp rise in harmonic tremors around Katla and Eyjafjallajökull volcano. I currently do not know what volcano is responsible for the spike in harmonic tremor. But this does not look like is a noise from the weather. But that can happen often this time of the year, as the wind forecast is good for all of Iceland at current time.

I will post more information if and when I get them.

SIL stations where the harmonic tremor rise can be seen.

Mið-Mörk
Eystri-Skógar
Lágur Hvolar (Currently most rise here for some reason)
Snæbýli
Saurbær
Ásmúli

Icelandic Met Office tremor web page.

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Grímsfjall continues to inflate

According to GPS data from GPS station located on top of Grímsfjall the volcano continues to inflate. Now it is about 80mm and does not seems to go much higher then that for some reason. Since Grímsfjall has stopped to inflate up at the moment it is currently inflating in other directions. The automatic GPS data clearly shows that the inflation is now moving south but is interestingly is holding it east-west movement. I am not clear on why that is the case at the moment.

Data: GFUM ISGPS