The Sciara del Fuoco is the only place, at least during the last 2000 years, where the explosion products from the Stromboli summit craters accumulate.
In fact, the latter are not perfectly centred in the volcanic cone, but a little further north, right at the top of the Sciara del Fuoco. Since it is a very steep slope, the blocks, bombs and lapilli emitted during the explosions roll down and fall back into the sea.
The same thing, however, also happens when one or more lava flows are emitted from the summit craters: they begin to flow on top of the loose material of the Sciara and often reach the sea.
Below the sea’s surface, the volcano maintains its conical shape. Therefore, the products can continue “rolling” or sinking slowly. This happened during the eruptions of 2002-03, 2007 and 2014.
However, the 2002-03 eruption of Stromboli was a turning point in the perception of volcanic risk, at least for this volcano. In fact, at the end of 2002, lava flowed on top of the Sciara del Fuoco, reaching the sea and continuing to sink into the submerged part of the Sciara. However, if you try to put a rigid and very heavy mass on top of a very steep slope of sand and loose material, sooner or later you can expect landslides. This situation occurred on 30 December 2002, when a large block of the Sciara del Fuoco collapsed below sea level, pulling part of the Sciara above sea level with it.
This landslide caused a small tsunami , which hit the seafront of the town of Stromboli, but it was also recorded along the Tyrrhenian coast of Calabria and Sicily.