Technology for early detection of earthquakes with submarine cables?

Submarine cables are laid in the Pacific and Atlantic Oceans to establish intercontinental communication. A study on early detection of earthquakes using these submarine cables was published in the journal Science.

This is a method of detecting earthquakes with only the existing fiber optic cables already installed on the sea floor without installing additional equipment announced by the California Institute of Technology research team. The research team measured the transmitted pulse distortion from December 2019 to September 2020 using a Google private submarine cable, Curie, which connects California and Chile. Through this, it was confirmed that when an earthquake occurs, polarization is generated in the optical pulse as if a submarine cable pulls.

According to the research team, it is possible to detect seismic wavelengths in the range of 5 to 10 mHz around submarine cables, and it has already succeeded in detecting 20 medium and large earthquakes or 7.5 earthquakes on the Richter scale in southern Mexico. It is also said to have detected waves created by sea storms. Not only earthquakes but also tsunami detection is possible.

The research team admits that there is still difficulty in detecting the earthquake occurrence point, but argues that this technology does not require additional equipment, so there is no risk such as data modulation and equipment theft. This technology can increase social benefits without affecting the existing system. He added that it will focus on improving detection accuracy and reducing noise in the future. Related information can be found here.