Underwater Seismology Using Submarine Dark Fibres

We review our recent work on chirped-pulse distributed acoustic sensing (DAS) for the characterization of teleseismic and microseismic activity, particularly in submarine environments. We show that this tool may bring orders-of-magnitude more seismic data from the sea bottom, that could lead to a new understanding of the deep Earth's interior. We show the detection of an M8.2 earthquake occurred in the Fiji Islands in August 2018, using an ocean-bottom DAS array located >16000 km away from the earthquake. The acquired signals are compared with the spectrogram of a nearby broadband seismic station, showing major similar features between the two records. The results show the great potential of re-using already-deployed telecommunication fibre network for distributed teleseism monitoring.