Frequently asked questions about Etna
What is the relationship between Etna and the earthquakes of the region?

This is another of those questions that are not very easy to answer. First, read an answer to a person who had asked about the general tectonic framework of Italian volcanism:

"Volcanism in Italy is generally due to the collision of the African and the Eurasian plates. However, few volcanoes in Italy are alike. The volcanoes farther north, in Latium and Campania, among which there is Vesuvius, may be in some manner subduction-related, but this is not clear. The volcanoes of the Aeolian Islands, such as Stromboli, Lipari and Vulcano, are at least in part due to subduction of the oceanic (?) crust of the Ionian sea under the Calabrian Arc, but there are some characteristics to Aeolian volcanism that do not agree with that picture. Etna may really be the product of a hot spot, but it is also related to a complex tectonic situation, with numerous major faults intersecting at the volcano. There are finally the volcanoes south of Sicily (Pantelleria and Linosa) which are due to continental rifting, similar to the East African Rift."

The following text (from Behncke 2001) is a modified excerpt from the book "The Southern Appennines: Anatomy of an Orogen" (edited by G. Vai and P. Martini) which was published by Kluwer Academic Press in late 2001; see also "Tectonic setting and geological evolution".

"Etna, Europe's highest (3310 m as of early 2002) and most active volcano, lies in a structurally highly complex, and not yet fully understood, setting which is reflected in the abundance and variety of - often controversial - models proposed for the volcano and its tectonic environment. Recently proposed hypotheses envisage as critical factors facilitating the uprise and eruption of magma: (1) dislocation between the "Malta-Sicilian block" and the Ionian basin (Gillot et al. 1994) in the framework of an asymmetric rifting process (Continisio et al. 1997); (2) extensional tectonics leading to the formation of a graben in the Catania Plain (Di Geronimo et al. 1978); (3) location of Etna at the intersection of a number of major structural lineaments (the most important being the Malta Escarpment and the Messina-Giardini fault zone; McGuire et al. 1997); (4) dilatational strain on the footwall of an east-facing normal fault in the Siculo-Calabrian rift zonewhere WNW-ESE-directed regional extension takes place (Monaco et al. 1997); (5) a hot spot (Tanguy et al. 1997; Schiano et al. 2001); (6) rollback of the lithospheric slab that is subducted below the Tyrrhenian Sea (Gvirtzman and Nur 1999) or magma ascent through a "slab window" (Doglioni et al. 2001). On the other hand, Lanzafame et al. (1997) postulate N-S-directed compressional tectonics affecting the southern part of Etna. This picture is further complicated by the effects of the presence of the voluminous Etnean edifice on the regional stress field, exerted both by the load of the volcano and by the movement of magma below and within it. Thus, volcanism and tectonics at Etna are clearly interacting, although the problem of cause and effect remains to be solved."

References

Behncke B (2001) Volcanism in the Southern Apennines and Sicily. In: Vai GB and Martini IP (eds) Anatomy of an orogen: the Apennines and adjacent Mediterranean basins. Kluwer Academic Publishers, Dordrecht-Boston-London: 105-120 (Etna: pp. 111-113).

Continisio R, Ferrucci F, Gaudiosi G, Lo Bascio D and Ventura G (1997) Malta escarpment and Mt. Etna: early stages of an asymmetric rifting process? Evidences from geophysical and geological data. Acta Vulcanologica 9: 45-53.

Di Geronimo I, Ghisetti F, Lentini F and Vezzani L (1978) Lineamenti neotettonici della Sicilia orientale. Memorie della Società Geologica Italiana 19: 543-549.

Doglioni C, Innocenti F and Mariotti G (2001) Why Mt Etna? Terra Nova 13: 25-31.

Gillot PY, Kieffer G and Romano R (1994) The evolution of Mount Etna in the light of potassium-argon dating. Acta Vulcanologica 5: 81-87.

Gvirtzman Z and Nur A (1999) The formation of Mount Etna as the consequence of slab rollback. Nature 401: 782-785.

Lanzafame G, Neri M, Coltelli M, Lodato L and Rust D (1997) North-south compression in the Mt. Etna region (Sicily): spatial and temporal distribution. Acta Vulcanologica 9: 121-133.

McGuire WJ, Stewart IS and Saunders SJ (1997) Intra-volcanic rifting at Mount Etna in the context of regional tectonics. Acta Vulcanologica 9: 147-156.

Monaco C, Tapponnier P, Tortorici L and Gillot PY (1997) Late Quaternary slip rates on the Acireale-Piedimonte normal faults and tectonic origin of Mt. Etna (Sicily). Earth and Planetary Science Letters 147: 125-139.

Tanguy J-C, Condomines M and Kieffer G (1997) Evolution of the Mount Etna magma: Constraints on the present feeding system and eruptive mechanism. Journal of Volcanology and Geothermal Research 75: 221-250.

Copyright © Boris Behncke, "Italy's Volcanoes: The Cradle of Volcanology"