First results after the deployment of a subsea geodetic monitoring system

Geodetic networks at sea are necessary to monitor active faults and the long term displacement of tectonic plates. iXblue has developed a new integrated subsea monitoring system: Canopus

The Canopus transponders are enable to regularly measure precisely the distance between the transponders that are in acoustic line of sight. The measurement are stored in a memory inside each beacon and can be collected from surface using acoustic modem. In collaboration with the IUEM, and in the framework of ERC Focus project, 8 Canopus beacons were deployed at each side of the North Alfeo Fault in Sicilia for a  4 years monitoring program. To prepare the deployment, a first experiment took place in Brest Bay in July 2019, and a second one in La Ciotat Bay in September 2020. Thanks to Delph subsea positioning software, simulations enable to confirm acoustic line of sight between beacons considering the local bathymetry, the sound velocity profile and the height of the transponders above the seabed. The final deployment took place in October 2020.  We present here the series of test and  simulations conducted before the final deployment and the first results after deployment.