Google recently conducted an experiment using its subsea fiber optic cables, which showed that it could be useful for earthquake and tsunami warning systems.
Valey Kamalov and Mattia Cantono from Google Global Networking posted a blog detailing how Google plans to detect earthquakes. “Last October, an idea came to us: we could detect earthquakes based on spectral signatures- performing a spectral analysis of Stokes parameters to look at frequencies that are typical of earthquakes,” they said in the blog post.
Google believes that its approach relies on technology that is widespread on today’s fiber optic networks. Millions of kilometres of fiber optic networks already span the globe, operated by governments, telecommunications providers, and technology companies, including Google. “By collaborating with the global subsea cable community, we may be able to improve the world’s ability to detect and research seismic activity around the world,” Google said in the blog post.
How Google can make it work: By using undersea cables
Google has a global network of undersea cables which makes it possible to share and search information “around the world at the speed of light.” “Fiber optic cables connect far-flung continents along the ocean floor, and much of the internet’s international traffic travels over these cables,” Google explained in the blog post.
Google first started working on this in 2013 but it was only in 2019 that Google conducted its first experiment. Initially, there was no state of polarization (SOP) changes that could detect 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!,” Google further said in the blog post. The state of polarization continued to show a sole for five minutes after the earthquake took place. This, as per Google, correlated to the travel time of seismic wave from Jamaica to the cable, and the duration of the spike was about 10 minutes.
Since then Google has been able to detect moderate-sized earthquakes in Mexico and Chile.
“We’re excited by the early success of detecting seismic events with subsea cables, which can improve our ability to observe both the Earth’s structure and earthquake dynamics,” noted the company in the blog post. However, this is just the beginning, according to the tech giant. The blog post further noted, “to create a robust earthquake monitoring system, researchers need advanced mathematics and data analytics, where advanced computing systems like Google Cloud can be instrumental.”