Lava flow Night time view of lava flowing from a small vent on Etna This vent is a hornito a relatively small outlet which is normally only throws out lava bombs On occasion the changing internal structure of the volcano may mean that a hornito becomes the easiest route for lava to reach the surface and becomes the site of an effusive eruption Etna is the largest active volcano in Europe Although internal pressure is normally released by gentle Strombolian activity Etna also has periodic episodes of intense lava production Photographed on November
