One of the most peculiar things I've ever seen on Etna
The amazing rock needle, or "spine", which formed during the 8 September 2011 paroxysmal eruptive episode of Etna's New Southeast Crater at the base of its cone, has already been shown in numerous photos here on Flickr, to some of which I have also created links in my previous post. I also posted a photograph taken by my friend Wolfgang Lübke just a few hours after the 8 September paroxysm.
On Monday 12 September 2011 I finally got a close look at that thing myself, during a visit to Etna's summit craters with Wolfgang Lübke. The "spine" has lost about one-third in height and quite some material has also been shed from its sides. Still it remains a most remarkable feature, something no one has seen at Etna until now, and whose formation required a rather unique mechanism whose exact details will remain forever mysterious. However, what is certain is that this "spine" - which during our visit on 12 September was some 15-20 m tall - consists of layers of volcanic rock fragments, scoriae and bombs, which are partially welded together. It is a piece of the flank of the cone that was disrupted by the latest paroxysms; this piece was somehow uplifted and rotated into a vertical position, possibly when it was swept along with flowing lava and ran into an obstacle.
Photo taken from the south side of the depression within which this rock needle is standing; the east rim of the New Southeast Crater is seen at upper left. This is a mosaic composed of four photos