Google and Alphabet CEO Sundar Pichai on Twitter informed that the tech giant has carried out an experiment using subsea fibre optic cables which is capable of detecting earthquakes and tsunamis early around the globe and be used as a warning system.

In a blog post by Google, it said although optic fibres for sensing applications are effective for up to 100 km, this technique works over tens of thousands of kilometres. The subsea fibre optic cables use existing fibre to detect disturbances on the seafloor.

"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 travelling at 204,190 kilometres per second," the blog post read.

Talking about how this would work, the blog post said, "the pulsing light encounters distortions as it travels thousands of kilometres across the cable. At the receiving end, the light pulses are detected, and the distortions are corrected by digital signal processing. One of the properties of light that are tracked as part of the optical transmission is the state of polarization (SOP). The SOP changes in response to mechanical disturbances along the cable and tracking these disturbances enables us to detect seismic activity."

Google said it faced early success of detecting seismic events with subsea cables, which can improve the ability to observe both the Earth’s structure and earthquake dynamics.

The subsea fibre optic cables can not only detect earthquakes emanating from tectonic plates, but it can also detect pressure changes in the ocean itself, which could help predict tsunamis.