Earthquakes, Das installed to study the earth with fibre optics

Ingv, Federico II and the Lucanian company Metis collaborate on the innovative project financed by the Pnrr and located in Tito in the Irpinia crater

3 October 2024

Installazione del rilevatore DAS nella sede dell azienda di telecomunicazioni Metis a Tito Scalo PZ

3' min read

Key points

Earthquake Observatory
Objective: create a constellation of monitoring stations
Great potential of fibre optics

3' min read

Experimenting with the use of optical fibre used for telecommunications as an innovative seismic sensor. This is the goal of the INGV and the Federico II University of Naples, which recently completed the installation of an acoustic sensing device (Das) in Tito Scalo, in the province of Potenza, where the telecommunications company Metis has made available to researchers a stretch of fibre optic cable about 20 km long.

We are talking about the Irpinia crater area, the one that was devastated by the 1980 earthquake. Scientific research has turned that area between central Campania and central-northern Basilicata into a magnifying glass to better understand the genesis of large earthquakes.

Earthquake Observatory

Das will be used by the Irpinia Near Fault Observatory (Nfo), which is the result of a collaboration between INGV and the University of Naples Federico II and is based in Naples at the same university. The observatory, set up as part of the European Plate Observing System (EPOS) and recently implenetrated and financed (1.9 million) by the PNRR Monitoring Earth's Evolution and Tectonics (MEET), aims to carry out state-of-the-art monitoring of the underlying fault system in this area, among those with the highest seismic hazard in Italy.

Evento sismico catturato dal sistema DAS lungo la fibra

Objective: Create a constellation of monitoring stations

There are two main actions: on the one hand, the transformation of individual seismic stations into constellations of stations, i.e. series of close sensors, capable of picking up local microseismicity even at extremely low magnitudes, and on the other hand, experimentation with the potential of normal telecommunication fibre optics to act as a seismic sensor.

Great potential of fibre optics

"The measurements come from a laser source that sends light pulses inside the fibre _ explains Gilberto Saccorotti, INGV researcher _ Every slightest deformation of the fibre modifies the optical path length of the pulses, and measuring this variation makes it possible to determine the deformation of the ground due, for example, to the passage of a seismic wave. The device is capable of making these observations hundreds of times per second, with a measurement point spacing of the order of a metre, distributed along fibres up to tens of kilometres long. This is an enormous amount of data compared to current seismometric networks, which is potentially capable of photographing the ground deformation associated with the seismic phenomenon in a much more detailed and continuous manner'.

"The Irpinia crater is the ideal location to test these new technological systems because the great availability of parametric networks that we have in this area will allow us to analyse the new data obtained, verify them and understand their potential _ adds Gaetano Festa, Professor of Physics at the University of Naples Federico II _ We are in a new field of research, but what we expect is a huge leap forward because it is like having thousands of sensors on the investigated stretch, providing continuous data in real time.

The first image obtained from the experiment demonstrates how the use of fibre optics for seismic monitoring represents the scientific challenge of the future because it produces a new 'snapshot' of the dynamics of the fault system in Irpinia that opens up new studies and new interpretations for a deeper understanding of earthquake genesis and seismic risk management.

Metis, a local SME offering fibre optics for inaccessible areas

A fundamental contribution to the success of the research project is that of Metis, a limited company based in Tito Scalo, which has given Ingv and Federico II 20 km of fibre optics. "We have a long-standing relationship with the Federico II _ says the project's technical manager, Domenico Carabotti _ and for some time we have been able to bring connectivity to areas that are difficult to reach". Metis is a small local company with around six employees.