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IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy
(S) - IASPEI - International Association of Seismology and Physics of the Earth's
Interior
JSS002 Oral Presentation 1759
Stromboli Island (Italy): tsunamis generated by submarine landslides
Dr. Alberto Armigliato
Dipartimento di Fisica, Settore Geofisica Universita di Bologna IASPEI
Stefano Tinti, Filippo Zaniboni, Gianluca Pagnoni
The strong volcanic activity of Stromboli island, located in South-East Tyrrhenian Sea (Italy), is well
known: the morphology of the volcanic complex has been deeply changed by the frequent catastrophic
events that characterized its history. The last one (or ones), in the Holocene, formed the Sciara del
Fuoco scar (in the North-Western flank of the island), an evident big depression that extends also under
the sea. The sliding mass had an estimated total volume of around 1 km3, and the simulations of such
(possibly multiple) event carried out by our group evidenced the impact of really catastrophic waves on
the coasts of South Italy. In addition to large disastrous events, minor failures take place recurrently in
the Sciara del Fuoco, due to accumulation of ejecta along the slope, to the steep angle typical of
volcanic flanks, to the tremors induced by volcanic activity: all these elements contribute to submarine
and sub-aerial mass instabilities. These have potential for tsunami generation as was shown by the
December 30th 2002 failures that occurred here. Big tsunami waves were set up that travelled all
around the island, reaching the height of over 10 meters and causing severe damage in the waterfront
area, but fortunately no casualties.These events justify the constant monitoring of the Sciara del Fuoco,
together with the large effort to study its characteristics and evolution, but this is not the only place of
Stromboli where mass failures are to be expected. Several submarine incisions were evidenced by
bathymetric surveys all around the island, that can be interpreted as results of past events and also can
be seen as possible source areas of future events. In this work we consider three alternative scenarios
for landslides generating tsunamis around Stromboli flanks, with volume comparable to the December
2002 events. The first is placed in the Strombolicchio plain, north of the island; the second is found near
the southern extreme of the island, at Punta Lena, and the third is located in the Eastern coast, in the
area named Forgia Vecchia. The landslide simulations is carried out through a Lagrangian block model
(UBO-BLOCK1) developed at the University of Bologna, while the computation of the tsunami generation
and propagation around the island and in the Aeolian Archipelago is performed through a finite-element
tsunami model (UBO-TSUFE), that was developed by the same research group.
Keywords: stromboli, landslide, tsunami