These pictures were taken from the cable deployment maneuver, during the FOCUSX1 cruise. We can see parts of the FOCUS project's first steps : connecting a 6-km long fiber optic cable to the seafloor observatory TSS (Test Site South) and then deploying the cable using a deep-water cable-laying system with a plow.The track of the cable crossed the North Alfeo Fault at three locations. Across the faults the cable was buried 20 cm in the soft sediments in order to increase coupling between the cable and the seafloor. Seafloor geodetic stations were deployed on both sides of the fault, to equally record small movements of the seafloor. Positioning of the cable and stations was made possible due to detailed bathymetric data acquisition using the ROV Victor6000.

 

The objective of the FOCUS (Fiber Optic Cable Use for Seafloor studies of earthquake hazard and deformation) project, funded by the ERC (European Research Council), is to study the adaptation possibilities of submarine telecommunication cables, which could prove to be a tremendous asset in large-scale seismological monitoring. The 5-year project aims to detect small (1 to 2 cm) displacements across the recently mapped North Alfeo Fault, located 20km from Catania, a 1-million-inhabitants urban area in Sicily. The studies rely on the Catania  EMSO (European Multidisciplinary water-column and Seafloor Observatory) station, located in 2100 m depth and connected to land by a 25 km long electro-optical cable.