The marine activities performed within the TOMO-ETNA experiment

The TOMO-ETNA experiment was planned in order to obtain a detailed
geological and structural model of the continental and oceanic crust beneath
Mt. Etna volcano and northeastern Sicily up to the Aeolian Islands
(southern Italy), by integrating data from active and passive refraction
and reflection seismic methodologies, magnetic and gravity surveys. This
paper focuses on the marine activities performed within the experiment,
which have been carried out in the Ionian and Tyrrhenian Seas, during
three multidisciplinary oceanographic cruises, involving three research
vessels (“Sarmiento de Gamboa”, “Galatea” and “Aegaeo”) belonging to
different countries and institutions. During the offshore surveys about
9700 air-gun shots were produced to achieve a high-resolution seismic tomography
through the wide-angle seismic refraction method, covering a
total of nearly 2650 km of shooting tracks. To register ground motion, 27
ocean bottom seismometers were deployed, extending the inland seismic
permanent network of the Istituto Nazionale di Geofisica e Vulcanologia
(INGV) and a temporary network installed for the experiment. A total
of 1410 km of multi-channel seismic reflection profiles were acquired to
image the subsurface of the area and to achieve a 2D velocity model for
each profile. Multibeam sonar and sub bottom profiler data were also collected.
Moreover, a total of 2020 km of magnetic and 680 km of gravity
track lines were acquired to compile magnetic and gravity anomaly maps
offshore Mt. Etna volcano. Here, high-resolution images of the seafloor, as
well as sediment and rock samples, were also collected using a remotely
operated vehicle.