Could a fibre-optic network be used in the future to help predict earthquakes? — AFP Relaxnews
In addition to providing high-speed Internet access, fibre optics could also help detect and measure the intensity of earthquakes. This technology is still in the development phase, but it has the potential to revolutionise a field in which seismographs were long the main tool.
Fibre optics technology is capable of detecting earthquakes of a magnitude 3.5 to 4.5 on the Richter scale. This discovery was made by geophysicists at the Institute of Geophysics at ETH Zurich, in collaboration with the Swiss Federal Institute of Metrology (METAS).
The optical fibre transmits light signals, which are disturbed when subjected to vibrations. The researchers therefore decided to use a well-known technology known as phase noise cancellation (PNC). This is a technique already used in the manufacture of certain audio headphones to reduce, or even almost totally eliminate, any ambient noise.
In this case, a signal is initially transmitted into the optical fibre, and then used as a reference for comparison, in return, with any partial signal that is returned. An algorithm then calculates the difference between the two signals, to determine the degree of vibration caused by recent seismic activity.
This approach offers many advantages, since in theory it can be applied to a large part of the world's landmass, or at least to those territories equipped with fibre optics, and this area is constantly expanding. In France, for example, 83% of households are within reach, with the aim of reaching 100% by 2030. Additionally, fibre is cheaper and easier to put into place than conventional seismographs. Fibre should also be more accurate, as it can detect vibrations over greater distances.
In France, researchers at the Institut de Physique du Globe de Paris (IPGP) are already using a high-speed submarine cable to listen in on seismo-volcanic activity in the Mayotte region.
Ultimately, using fibre to measure and analyse seismic vibrations could help prevent certain natural disasters, by enabling populations to be alerted more quickly if necessary and thus limiting the loss of human life.
Further research is needed to improve the reliability and accuracy of this technology, but it has the potential to revolutionise a field that today relies mainly on the use of seismographs.
These sophisticated devices record the slightest vibrations of the Earth, but are generally only operated around known high-risk zones and faults. In terms of coverage alone, fibre optics could be a game-changer. – AFP Relaxnews
