Google Earthquake detection with submarine cables.
                     Google Earthquake Detection With 
Submarine Cables
Introduction
• With the help of subsea fiber optic cables, Tech giant Google has developed a new way of detecting 
undersea earthquakes and tsunamis. 
• While this detection method already exists, the company claims that its methodology works over tens of 
thousands of kilometers as opposed to current techniques that are successful over distances of up to 100 
km.
Source: The Hindu
History
• The company in a blog post said the researchers worked in 2013 on how to use SOP data to better 
understand the deviations observed on a land-based terrestrial cable, but the project was abandoned as 
the environmental conditions created too much damage to detect seismic signatures.
Source: Google Cloud Blog Post
Uniqueness
• The company also claimed that the previous systems need special sensing fiber and special equipment, 
while the new fiber is based on the methodology used by the company to detect disturbances on the 
seafloor.
Source: WION
Fiber Optics
• It is known that fiber optic cables connect various continents along the seafloor and a great deal of 
international traffic travels over these cables. 
• Google uses those cables to exchange, scan, send , and receive information at the speed of light around 
the world.
Source: WION
How does this Work?
• The subsea fiber optic cables carry data at a rate of 204.190 kilometers per second as light pulses traveling. The pulsing light 
encounters distortions as it traverses the cable for thousands of kilometers. 
• The light pulses are detected at the receiving end, and the distortions are corrected by digital signal processing. Seismic 
activity is detected with the help of SOP (State of Polarization), due to the mechanical disturbances along the cable.
Source: ACACIA Communications
Submarine/ Subsea Cables
• A subsea fiber optic cable is a submarine communications cable placed between land-based stations on 
the seabed for transportation of telecommunications signals across oceans and sea.
Source: The Hindu
Google’s View on this Technology
• According to the business, the era of today is based on technology that is distributed across the fiber optic 
networks of today. 
• Hundreds of thousands of fiber optic networks are spread across the globe for this reason, and are run by 
states, telecommunications providers and companies such as Google.
Source: WIRED UK
2019 Research
• On the East Pacific Rise a 6.1 magnitude earthquake was recorded on March 22, 2020. The event took place 
this time at a distance of 2000 km from the company's cable. 
• A clear activity on the SOP has been reported. A 4.5 magnitude earthquake was recorded 30 km away from 
the company cable on March 28, 2020. This produced a brief spike in the operation on the SOP.
Source: France 24
Expectation
• The company also notes that this technique is just a demonstration as of now and more work needs to be 
done to understand the seismic data produced by the SOP as it drastically changes. 
• The data is based on magnitude, location and so on and is different for various seismic activity. 
Source: berkeley.edu
Conclusion
• Thus, the researchers will use advanced mathematics and data analytics to create a strong earthquake 
detection system, where Google Cloud could prove to be of great help as the technique works across tens of 
thousands of kilometers and relies on equipment already present in the existing fiber optic system, where 
data travels as light pulses at more than two lakh kilometers per second.
Source: CNet