Etna: the largest volcano in Europe and among the most active in the world

Etna is the largest volcano in Europe (geographically speaking), and among the most active volcanoes in the world. Its eruptions occur both at the top, where there are currently four craters, and from the sides, up to heights of a few hundred meters above the sea level. Summit activity can take place for many years with few interruptions (eg 1955-1971; 1995-2001; 2011-2018), and often characterizes the intervals between a flank eruption and another. These intervals can last from a few months to more than 20 years, although in the last 40 years the average interval between flank eruptions has been about 2 years. The duration of a flank eruption can be a few hours, but in other cases it can exceed a year (1991-1993: 472 days; 2008-2009: 419 days).