[winoneforthegipper]

Actually, Godzilla not to get in this fight but....lol

The Helicorders and webicorders do not record harmonic tremors quite like that which we are familiar with via regular seismograph signatures.

These events are captured as such on a webicorder.

http://i710.photobucket.com/albums/ww109/volcanism2/alaska/REF_2009-03-26.jpg

Note before Redoubt's first large eruption in March and throughout Feb. of last year, harmonic tremors were more the norm than the swarms you see on that graph prior to eruption. The harmonics oscillated as well but you can clearly see their signature on the webicorder.

The first large one at the top of graph led to a medium size expulsion of ash and vapor. More importantly, a series of harmonics started the quake swarm right before the first large explosive event.

[winoneforthegipper]

Here is a graph of Redoubt’s webicorders showing the start of the Harmonic tremor stage. The settings on the webicorder were high so they appear a bit differently than the ones in march, where they had actually lowered them due to decreased activity.

http://i280.photobucket.com/albums/kk171/volcanism/alaska/redoubt_30jan.png

As you can see quite different compared to seismos.

[Godzilla]

Actually, Godzilla not to get in this fight but....lol

Yeh, right, sure ;)

I can see (given the quality of the image)I see what could be harmonics beginning at about 14:45 and continuing to about 17:19 with increasing sharp, short seisimic events superimposed.

The following makes a comparison between common seismic forms

Now the issue is whether or not the seismographs at Ystone are seeing magma moving or only tectonic quakes (or the very similar shallow volcanic quakes - both involve rock movement) - the evidence points to tectonics. With all the study of harmonic tremors since Mt. St. Helens, this is one wave form that would get the notice of the seismologists.