This screenshot shows the first sight i got when i woke up this morning. Bruce Stout had been watching the event from the time it started and had left comments on VC which made me aware of what is going on. Etna changed its behavior the last days and displayed a 4th paroxysm today early in the morning after being active twice yesterday.
INGV analysed the paroxysms of the 20 in this articles in Italian and English. You can most likely expect a new report on todays events at http://www.ct.ingv.it/ a little later. Dr. Boris Behncke made some comments over at Eruptions where Erik had been writing a post on Etnas behavior too yesterday:
Yesterday someone zoomed in one Radiostudio7 cam and so i could take nice screenshots…
This picture was created out of the best screenshots i got of the Radiostudio7 cam yesterday.
Check the lower right side of this image. I have not seen that spot before!
I´d like to paste some of the comments into this post to start a discussion:
Bruce noticed that same lava break-out feature has reappeared:
http://i40.photobucket.com/albums/e211/NoEnz/Bildschirmfoto2013-02-21um061250_zpsa0fbc1d1.png but Newby could be assured that no people are in danger because the ava flows down into an uninhabitet valley called Valle del Bove.
Bruce Stout says: February 21, 2013: Good morning, everyone, (yawn), oh look, Etna is at it again (no. 4) instant wake-up call.
Initial thoughts on Etna. A while ago I postulated that the periodicity in Etna’s paroxysms was caused by a steady magma feed into a piston like chamber with a narrow opening to the surface (this piston might be nothing more than the conduit itself). In this case the mechanism would be that magma enters the piston, starts to degass due to drop in pressure and slowly fills the piston until the pressure and volume was high enough to clear out the flimsy plug left by the last event. The built-up pressure in the piston coupled with rising levels of exsolution of gases leads to the fountaining as the piston empties itself. Rinse and repeat.
Now, if this is correct, why the sudden increase in the frequency of these paroxysms? Two possibilities come to mind: Faster rate of magma feed from below or a smaller piston.
Working in favor of the latter, is that the volumes of these paroxysms seem to be smaller than the previous series (though I am flying on the seat of my pants on this one, just guessing from the videos/webcams). It is most likely a combination of both faster feed and a smaller piston volume in the upper conduit. If higher feed, we might see a flank eruption at some stage which Boris once said often follows such series of paroxysms.
Just some random thoughts put here for discussion…
February 21, 2013 at 05:04
Well, bang goes that theory… this paroxysm is back to the old levels:
Webcams are offering some very atmospheric shots as the wind is blowing the cloud towards the cam, obscuring the vent:
Spica: Ok the tremor is down again. The event seems to be over.
Bruce took a screenshot of the tremor being at 121 i saw it at 123 and when you check the graph now it shows that is was never as high as with the first paroxysm on the 19th. Can anyone explain this to me, this is not the first time i saw this behavior of the tremor graphs and i never understood it.
Boris mentioned on eruptions that it is not the first time Etna shows many paroxysm. In 2000 it started paroxysms in January and till late August the count ran up to 66 ! of those explosive events. I am bringing the webcam list over again so you have a chance to watch the show on your own.
- INGV Etna cams. From this link you can also find the Tremor and Seimology of Etna, cams and more on Stromboli and the Aelion islands.
- Collection of Etnacams by Etnatrekking.
- Etna Guide cam
- Etna Web cam
- Radiostudio 7 cams
- Live cams with Sound, Etnawalk, does not work in all browsers.
- Over 60! webcams of Sicily. Not all of them pointing at Etna
- The Hotel Corsano at Etna has a nice list of cam.
- Lave Cam
- Several Etna webcams, thermalcam and tremorgraph, all on one page, by volcanodiscovery.com
- Etnaweb cams
One more screenshot for all who missed the show!
taken from the Lave cam: http://www.lave-volcans.eu/webcams_etna.php?numero=2
Name those Volcanoes Riddle
4 volcanoes 4 points
No 1 – Does it serve as a warning beacon for ocean going ships? Its nickname includes the name of an ocean. SOLVED
No 2 – This volcanic island’s artifacts/treasures, specifically A & A, can be found in both the B M and the L. A & A are the names of ancient statues. SOLVED
No 3 – Here the salty craters hold a current ‘known’ subaerial world record. SOLVED
No 4 – During a warm, summer month in 2012 its summit displayed an historic ‘first’. Icelandic volcano. SOLVED