In the areas affected by the 1980 earthquake, researchers have created an Observatory capable of exploiting the potential of optical fibre used in telecommunications for the observation and study of soil deformation associated with seismic phenomena.
As part of the experimentation on the potential of the optical fiber used for telecommunications to be exploited also as an innovative seismic sensor, the researchers of theNational Institute of Geophysics and Volcanology (INGV) and University of Naples Federico II have recently completed the installation of an acoustic detection device (DAS) in Irpinia, in Tito Scalo (PZ), where the telecommunications company Metis has made available to researchers a stretch of optical fiber approximately 20 km long.
In Italy, talking about Irpinia means talking about an earthquake: after the devastating earthquake of 23 November 1980, scientific research transformed the area between central Campania and central-northern Basilicata into a magnifying glass to better understand the genesis of large earthquakes.
It is in this context that theIrpinia Near Fault Observatory (NFO), the result of the collaboration between the INGV and the University of Naples Federico II. The Observatory, born within theEuropean Plate Observing System (EPOS) and recently funded by the PNRR Monitoring Earth's Evolution and Tectonics (MEET) project, aims to create in this area, one of the most seismic risk areas in Italy, a state-of-the-art monitoring of the underlying fault system.
The main actions are two: on the one hand the transformation of single seismic stations into constellations of stations, that is, into series of closely spaced sensors, capable of capture local microseismicity even with extremely low magnitudes, and on the other hand the experimentation on the potential of the normal telecommunication optical fiber to act as a seismic sensor.
“The measurements come from a laser source that sends light pulses into the fiber”, explains Gilberto Saccorotti, researcher at INGV. “Each minimal deformation of the fiber modifies the length of the optical path of the pulses and the measurement of this variation allows us to determine the deformation of the ground due, for example, to the passage of a seismic wave. The device is able to carry out these observations hundreds of times per second, with a spacing of the measurement points in the order of a meter, distributed along fibers that are even tens of kilometers long. This huge amount of data, compared to current seismic networks, is potentially capable of photographing in a much more detailed and continuous manner the ground deformation associated with the seismic phenomenon.".
“Irpinia is the ideal place to test these new technological systems because the large availability of parametric networks that we already have in this area will allow us to analyze the new data obtained, verify them and understand their potential”, he adds Gaetano Feast, 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 in quality because it is like having thousands of sensors available on the investigated stretch, which provide continuous data in real time.".
The first image obtained from the experimentation already shows how the use of optical fibre for seismic monitoring represents the scientific challenge of the future because it returns an unpublished "photograph" of the dynamics of the Irpinia fault system that opens up to new studies and new interpretations for a deeper understanding of the genesis of earthquakes and for the management of seismic risk.
Useful links:
National Institute of Geophysics and Volcanology (INGV)
University of Naples Federico II
Department of Physics-UniNA
Irpinia Seismic Network - data and products
PNRR-MEET project
EPOS Italy
As part of the experimentation on the potential of the optical fiber used for telecommunications to be exploited also as an innovative seismic sensor, the researchers of theNational Institute of Geophysics and Volcanology (INGV) and University of Naples Federico II have recently completed the installation of an acoustic detection device (DAS) in Irpinia, in Tito Scalo (PZ), where the telecommunications company Metis has made available to researchers a stretch of optical fiber approximately 20 km long.
In Italy, talking about Irpinia means talking about an earthquake: after the devastating earthquake of 23 November 1980, scientific research transformed the area between central Campania and central-northern Basilicata into a magnifying glass to better understand the genesis of large earthquakes.
It is in this context that theIrpinia Near Fault Observatory (NFO), the result of the collaboration between the INGV and the University of Naples Federico II. The Observatory, born within theEuropean Plate Observing System (EPOS) and recently funded by the PNRR Monitoring Earth's Evolution and Tectonics (MEET) project, aims to create in this area, one of the most seismic risk areas in Italy, a state-of-the-art monitoring of the underlying fault system.
The main actions are two: on the one hand the transformation of single seismic stations into constellations of stations, that is, into series of closely spaced sensors, capable of capture local microseismicity even with extremely low magnitudes, and on the other hand the experimentation on the potential of the normal telecommunication optical fiber to act as a seismic sensor.
“The measurements come from a laser source that sends light pulses into the fiber”, explains Gilberto Saccorotti, researcher at INGV. “Each minimal deformation of the fiber modifies the length of the optical path of the pulses and the measurement of this variation allows us to determine the deformation of the ground due, for example, to the passage of a seismic wave. The device is able to carry out these observations hundreds of times per second, with a spacing of the measurement points in the order of a meter, distributed along fibers that are even tens of kilometers long. This huge amount of data, compared to current seismic networks, is potentially capable of photographing in a much more detailed and continuous manner the ground deformation associated with the seismic phenomenon.".
“Irpinia is the ideal place to test these new technological systems because the large availability of parametric networks that we already have in this area will allow us to analyze the new data obtained, verify them and understand their potential”, he adds Gaetano Feast, 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 in quality because it is like having thousands of sensors available on the investigated stretch, which provide continuous data in real time.".
The first image obtained from the experimentation already shows how the use of optical fibre for seismic monitoring represents the scientific challenge of the future because it returns an unpublished "photograph" of the dynamics of the Irpinia fault system that opens up to new studies and new interpretations for a deeper understanding of the genesis of earthquakes and for the management of seismic risk.
Useful links:
National Institute of Geophysics and Volcanology (INGV)
University of Naples Federico II
Department of Physics-UniNA
Irpinia Seismic Network - data and products
PNRR-MEET project
EPOS Italy
Figure 1: Installation of the DAS detector at the headquarters of the Metis telecommunications company in Tito Scalo (PZ) 
Figure 2: Installation of the DAS detector at the headquarters of the Metis telecommunications company in Tito Scalo (PZ) 
Figure 3: A seismic event captured by the DAS system along the fiber