Earth’s Surface Deformation on Mount Etna: GPS Measurements, Interpretation, Relationship to the Mode of Volcanism

Abstract

We present results from a study of lateral Earth's surface deformation and vertical movements in the area of the Mount Etna active volcano (Sicily, Italy) based on observations by global satellite navigation systems in 2011–2017 at time intervals of 24 hours at sparse stations of the regional geodetic network. The study of Mount Etna is especially important because (1) the volcano stands in a densely populated area, (2) the eruptions are nearly continuous, and (3) the location of the volcano is inconsistent with plate tectonic concepts. Subregional trends have been identified in the deformation of the area of study. Extension was recorded, not only around the summit crater, but also far from it, in the Ionian Sea. This circumstance suggests the existence of an extensive plumbing system at depth whose sources are far from the active summit crater. We discuss geological and geophysical survey results of the coastal area and the sea area in the region. It is shown that Earth’s surface deformation can be suitable studied from observation points of the existing networks that are rather distanced from each other, but cover a large area.