Marine Geophysics and Hydroacoustics

Geohazards off Southern Italy

The continental margins of southern Italy are located along converging plate boundaries, which are affected by intense seismicity and volcanic activity. Most of the coastal areas experienced severe earthquakes, landslides, and tsunamis in historical and/or modern times. The most prominent example is the Messina earthquake of Dec. 28, 1908 (Ms=7.3; 80,000 casualties), which was characterized by the worst tsunami Italy experienced in the historical time (~2000 casualties). More... It is, however, still unclear, whether this tsunami was triggered by a sudden vertical movement along a major fault during the earthquake or as a result of a giant marine slide initiated by the earthquake. The recurrence rates of major landslides and therefore the risk associated with landslides is also unknown. Based on detailed bathymetric data sets collected by Italian colleagues in the frame of the MaGIC Project (Marine Geohazards along the Italian Coast), seismic data (2D and 3D) and gravity cores were collected in three working areas (The Messina Straits, off Eastern Sicily, the Gioia Basin) during R/V Meteor Cruise M86/2 (Dec2011/Jan2012). A dense grid of new 2D-seismic data in the Messina Straits allows mapping fault patterns in great detail. One interesting outcome in this context is the identification of a set of normal faults striking in an EW-direction, which is almost perpendicular to the previously postulated faults. This EW-striking faults seem to be active. The area off eastern Sicily is characterized by numerous landslides and a complex deformation pattern. A 3D-seismic data set has been collected during the cruise using the so called P-cable in order to investigate these deformation patterns in detail.

Bathymetry and Topography of Mt Etna and the continental margin (Source: Felix Gross, CAU Kiel).

Topography and bathymetry of Mt Etna and the continental margin, and the location of the Marine Geodesy Array (Source: Felix Gross).

Based on the findings from M86/2, the new project Marine Geodesy offshore Mt Etna (MaGOMEt) led by Morelia Urlaub (GEOMAR), Sebastian Krastel and Felix Gross was established. The aim of this project is monitor the deformation and flank’s movement offshore Mt Etna. During R/V Poseidon Cruise POS496 (Mar-Apr 2016) a variety of seafloor monitoring devices were deployed and additional high-resolution 2D reflection seismic lines were gathered. The long term monitoring systems include a marine geodetic system, as well as ocean bottom seismometers and ocean bottom tiltmeters. The marine geodetic system will be operated for 3 years at the submerged continental margin offshore Mt Etna and will be recovered in 2019.

Ocean Bottom Seismometers (OBS) onboard of RV POSEIDON during cruise POS496 (Source: Felix Gross, CAU Kiel).

Ocean Bottom Seismometer and other equipment aboard RV Poseidon (Source: Felix Gross).


All findings from this project are the basis for the project Ocean Hazard Risk Assessment.

Contact person for the project: Felix Gross

Partner institutes:

  • GEOMAR Helmholtz Centre for Ocean Research Kiel
  • La Sapienza University of Rome
  • University of Malta
  • INGV Catania

 

Cruises:

  • FS Poseidon – POS496 – Mar. 2016 – Apr. 2016 – Offshore Mt Etna, Italy
  • RV Meteor – M86/2 – Dec. 2011 – Jan. 2012 – Offshore Sicily / Strait of Messina, Italy

 

Most relevant publications:

  • Fu, L., M. Heidarzadeh, D. Cukur, F. L. Chiocci, D. Ridente, F. Gross, J. Bialas, and S. Krastel (2017), Tsunamigenic potential of a newly discovered active fault zone in the outer Messina Strait, Southern Italy, Geophys. Res. Lett., 44, 2427–2435, doi:10.1002/2017GL072647
  • Gross, F., Krastel, S., Geersen, J., Behrmann, J. H., Ridente, D., Chiocci, F. L., Bialas, J., Papenberg, C., Cukur, D., Urlaub, M. und Micallef, A. (2015) The limits of seaward spreading and slope instability at the continental margin offshore Mt Etna, imaged by high-resolution 2D seismic data Tectonophysics. DOI 10.1016/j.tecto.2015.11.011
  • Gross, F., Krastel, S., Chiocci, F. L., Ridente, D., Bialas, J., Schwab, J., Beier, J., Cukur, D. und Winkelmann, D. (2014) Evidence for Submarine Landslides Offshore Mt. Etna, Italy In: Submarine mass movements and their consequences 6. , ed. by Krastel, S., Behrmann, J. H. und Völker, D. Advances in Natural and Technological Hazards Research, 37 . Springer, Dordrecht, pp. 307-316. ISBN 978-3-319-00971-1 DOI 10.1007/978-3-319-00972-8_27

RV Poseidon in front of Mt Etna during cruise POS496 (Source: Felix Gross, CAU Kiel).

RV Poseidon in front of Mt Etna (Source: Felix Gross).