Etna: Earthquake swarm in the northeast

Yesterday evening an earthquake swarm manifested on Etna’s northeast flank. The INGV reports 8 earthquakes with magnitudes from 2. The two strongest quakes were on M 3.2. The epicenters were located 5 km southwest of Linguaglossa. The hypocenters were very flat. The depths vary between 0 and 1 km. This is very unusual, normally the quakes are at least 4-5 km deep. The INGV does not indicate how many weaker quakes there have been for 2 days.

Probably they are tectonically caused earth tremors along the Pernicana fault system. Quakes here are not new. In the past they often signaled that Etna is preparing for a major eruption. However, it is not really possible to narrow down the time frame when an eruption is likely to occur.

The best known example happened in 2002. On September 22nd there was an earth tremor of magnitude 3.7. On October 26th a massive swarm quake started. One day later the flank eruption started. A scenario that could repeat itself at any time, even if the probability is not very high.