Google Says It Might Be Possible to Detect Earthquakes, Tsunamis With Submarine Cables

According to Google's experiment using one of its subsea fibre optic cables, it could be useful for earthquake and tsunami warning systems.By Krishna SinhaChaudhury, Times Now News
July 17, 2020

According to Google‘s experiment using one of its subsea fibre optic cables, it could be useful for earthquake and tsunami warning systems.

Is it possible to detect earthquakes with submarine cables? Well, Google thinks it might be possible. According to the company's recent experiment using one of its subsea fibre optic cables showed that it could be useful for earthquake and tsunami warning systems around the globe. Optical fibre have been used since long for sensing applications. But whereas most of these techniques are effective over distances of up to 100 km, the tech giant has now developed a technique that works over tens of thousands of kilometres.

And while previous approaches required special sensing fibre and special equipment, Google is using existing fibre to detect disturbances on the seafloor. Its technique relies on equipment that is present on the vast majority of the world’s existing fibre optic systems, so it is broadly applicable.

“Fibre optic cables connect far-flung continents along the ocean floor, and much of the internet’s international traffic travels over these cables. Google’s global network of undersea cables makes it possible to share, search, send, and receive information around the world at the speed of light. These cables are built using optical fibres that carry data as pulses of light traveling at 204,190 kilometres per second,” Valey Kamalov, Google Global Networking and Mattia Cantono, Google Global Networking wrote in a blog post late on Thursday.

According to Google, in October 2019, it was struck by the idea that earthquakes could be detected based on spectral signatures — performing a spectral analysis of Stokes parameters to look at frequencies that are typical of earthquakes.

Early tests

In late 2019, Google began monitoring SOP on some of its global submarine cables. During the initial field trial, the company observed that SOP was remarkably stable, even after the signal traversed 10,500 km. An ocean floor is mostly a quiet place.

“For several weeks, the ocean floor was perhaps too quiet, showing no SOP changes that would indicate an earthquake. Then, on January 28, 2020, we detected a magnitude 7.7  earthquake off of Jamaica — 1500 km away from the closest point of one of our cables. A plot of SOP over time showed a pronounced spike at a time stamp approximately five minutes after the earthquake occurred, correlating to the travel time of the seismic wave from Jamaica to the cable, and the duration of the spike was about 10 minutes,” Kamalov and Cantono added.

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