Towards continuous fibre-optic monitoring in the oceans with submarine telecommunications cables the SUBMERSE project

In the last few years, a number of technologies to use fiber optic cables as sensing devices have been established, among them Distributed Acoustic Sensing (DAS) and State-of-Polarisation (SoP). The potential of these technologies for monitoring a range of Earth System parameters in submarine cables has been demonstrated through several pilot experiments, but full integration with telecommunication infrastructure has not yet been achieved. The SUBMERSE (SUBMarinE cables for ReSearch and Exploration) project links Research and Education Networks (RENs), universities, research institutes and industry to establish multi-method monitoring along submarine optical telecommunication cables at several key oceanic cable routes branching off from Sines in Portugal, Madeira, Svalbard and in the Ionian Sea, and in addition the Transatlantic cable between Fortaleza and Sines. Those pilot sites should serve as a blueprint for establishing continuous monitoring services along many more cables. The project comprises technical developments for integrating DAS and SoP measurements, for establishing differential SoP measurements between repeaters and for operating DAS in a co-existence mode, i.e., in fibers also carrying telecommunications traffic. Furthermore, a range of geoscientific and marine biology use cases are included, which seek to establish code/services for monitoring earthquakes and tsunamis, tracking whales, measuring the sea state and other Earth System variables. The data collected by SUBMERSE will be distributed according to FAIR principles through established community-specific distribution channels such as EIDA for seismological data, with exceptions for security sensitive time periods, spatial or frequency ranges. The presentation will present some example data and methodological developments in the context of this project. Furthermore, an outlook on the seismological real-time and archive products will be provided.