Influence of crust type on the long-term deformation of a volcano: example from Mt. Etna (Italy)

The volcanic areas experience the greatest deformationin term of velocity and spatiotemporalvariability. Cyclic episodes of short-term inflationand deflation, registered during eruptions, are relatedto magma chambers or dykes migration.Long-term deformations are ascribable to intrusionof large subvolcanic bodies into the crust oreven to sub-crustal processes like the rise of amantle plume. Unfortunately, is not always possibleto discriminate among all these processesbecause they superimpose in space and in time.In this research, bringing the example of Mt.Etna volcano (Italy), we highlight the existenceof a source of deformation not directly related toa volcanic process, but that is rather related tothe nature of the crust hosting the volcanism.The occurrence of “anorogenic” volcanism suchMt. Etna in the collisional context of the Central-Mediterranean area can sometimes appear anomalous(Lustrino et al. 2011), and is a part of whythe tectonic origin of volcanism of Mt. Etna isstill debated. Also debated is the nature of thecrust on which Mt. Etna emplaced about 500 ka.Several authors suggest that this crustal blockis not continental but it is rather a remnant ofan old, weathered oceanic crust (Sapienza andScribano 2000; Ciliberto et al. 2009; Manuella etal. 2013; Barreca 2014).In this work we are able to accurately describeand model the altimetric distribution of a stratigraphicmarker within the Etnean substratumand, taking into account the geological featuresof the area, we identify the different individualQuaternary deformation processes that have interacted.