The researchers propose to use existing undersea fiber optic cables as a seismic detection tool.
The first results are particularly encouraging, as a team of researchers from Rice University and the University of California have just revealed in the journal Nature how to easily set up an underwater seismic detection network using only fiber-optic cables. under the sea.
Monitoring seismic activity is a complex task because detectors are needed everywhere. Until now, the oceans and seas (accounting for two-thirds of the world) have never been equipped with seismic detectors because seismometers are precise instruments that are difficult to install and maintain under kilometers of water, so no seabed monitoring system has been put in place yet.
But US researchers recently ended the problem by demonstrating how to convert existing undersea fiber optic cables into seismic networks, providing an unprecedented view of all the motions. tectonics of the Earth. More importantly, we won’t need to try to install new equipment, but just take advantage of the existing offshore cables that people use when connecting to the internet.
The principle is that optical fibers send digital data in the form of light. Light can be scattered or distorted if the cable moves or changes direction. By monitoring this phenomenon, we can know where and with how many nanometers the cable bends. Even this is more efficient than a good old ground-based seismometer.
Best of all, there is no need to add additional equipment along the length of the cable when we simply need to connect the seismograph to the end of the cable, as Nathaniel Lindsey, lead author of the study commented.
When the tests are complete, the new system will be applied to optical cables operating on the seabed, effectively eliminating a critical blind spot under the ocean.