New advancements in fibre optic technology have opened new opportunities for earthquake detection
Researchers have developed a new algorithm that uses a network of fibre optic cables to turn them into sensors that can detect seismic events.
These cables are usually used for global telecommunications, cable television and internet services.
This was made possible through recent technological advancements, but putting the method into action has proven difficult.
Boosting seismometer measurements
Geophysical Journal International examined the advantages and challenges of using fibre optic data to enhance traditional seismometer measurements.
The new measures aren’t just there to predict earthquakes but can also be used to detect seismic activity associated with erupting volcanoes, geothermal boreholes and glacier icequakes.
Researchers used Distributed Acoustic Sensing (DAS), a technology that allows fibre optic cables to monitor vibrations and sound waves along their length. As fibre optic cables are already used in populated areas and across oceans, they are a good fit for creating a global seismic monitoring network.
Earthquakes are usually detected using seismometers, but these can be expensive and hard to work. Fibre optic networks, however, offer more detailed seismic data from a wider network, which could be quicker and more accurate.
Challenges of detecting earthquakes through fibre optics
Fibre optics cables are sensitive to strain only along their length, but usual seismometers can measure ground motion in three dimensions.
This can make it harder to detect earthquakes as fibre optic cables are more responsive to slower seismic waves (S-waves) than the faster, more damaging primary waves (P-waves).
Fibre cables are also often located in noisy urban environments, which could make it brutal to detect earthquake signals as they become hard to distinguish between other vibrations like traffic or industrial noise.
The new algorithm combines data from fibre optic cables and traditional seismometers to overcome these issues.
Using data from both sources gives it a better chance of detecting seismic events and accurately locating their origins.
The main advantage of this approach is using data generated by fibre optic networks while also addressing issues like noise interference.
How does this new algorithm work?
This algorithm takes the energy the sensors detect and traces it back through space and time to pinpoint seismic sources.
This new technique is very effective even in noisy environments; this is because earthquake signals are usually more coherent than random noises.
For example, monitoring volcanic eruptions or geothermal activity in real-time could provide useful insights into these dynamic processes, helping scientists understand potential hazards and take preventive actions if necessary.
Despite its promise, there are still challenges to address before fibre optic networks can become a reliable tool for global earthquake monitoring.
The complexity of fibre network geometries and the large volumes of data generated are significant obstacles. However, the new algorithm offers a practical solution, running in real-time on the data tested. This is a significant step toward overcoming the data processing challenges associated with fibre optic seismic monitoring.
Integrating fibre optic technology with traditional seismic monitoring could revolutionise how we detect and track earthquakes. By using existing infrastructure and improving data processing techniques, this new approach could provide more detailed and accurate earthquake alerts.
While further improvements are necessary, the potential benefits of this innovation, especially in terms of early warning systems and disaster preparedness, are enormous. Researchers continue to explore ways to optimise fibre optic earthquake detection, and the open-source nature of the algorithm allows the broader scientific community to build on this work, paving the way for more resilient and responsive seismic monitoring systems worldwide.
