After the violent paroxysm during 10-11 Nov 2013, the New SE crater continued to produce regular explosions, and, to our great surprise, we could observe during the afternoon of 11 Nov, that it often made fantastic vortex rings (steam rings or "smoke rings") that were blown eastward by strong Ponente.
Most likely, the eruption had changed the morphology of the vent into a way (into a particularly well circularly shaped form?) that allowed it to produce this rare phenomenon. And being Etna, she exaggerates: not only one ring every now and then, but she made dozens if not hundreds during a few hours, often in a row.
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