Micro-seismic monitoring after the shipwreck of the Costa Concordia at Giglio Island (Italy)

A micro-seismic network was used for monitoring the wreck of the Costa Concordia cruise ship, wrecked and run agrounded along the Giglio Island coasts during the night of 13 January 2012, until its removal. The seismic traces were processed by means of real-time and “a posteriori” procedures to detect transients that could be ascribed to wreck movements on the sea bed to integrate this information in an early warning system for assessing the wreck stability. After a first discrimination of the transients using amplitude criteria we proceeded to the localization of the detected signals to focus the attention only on the transients originated in the shipwreck resting area. The results showed that most of the events localized on the wreck were likely related to human work activities or sudden internal brittle failure but not to displacements on the seafloor. Instead, the displacements are associated to the impact on the vessel of great sea storms which approach were well correlated with the increasing seismic noise at low frequency. The carried out procedures based on this unique dataset represent an opportunity to test seismic monitoring techniques also in not usual engineering context to support emergency management activities.