Scientists are hoping the fibers millions of people use to communicate can also be used to monitor incoming earthquakes. Although less sensitive than the seismometers currently used by scientists, Biondo Biondi, a professor of geophysics at Stanford University’s School of Earth, Energy & Environmental Sciences, says the fibers are an inexpensive method to monitor vast areas. “We can continuously listen to–and hear well–the Earth using pre-existing optical fibers that have been deployed for telecom purposes,” Biondi said. According to Laser Focus World, Biondi plans to turn San Francisco’s fiber network into an earthquake observatory.
For the past year, Biondi has studied how the stresses of seismic events affect fiber strands, and how these movements can be used to gather information on the size and direction of these events. So far, researchers are using a three mile optical fiber loop on the Stanford, CA campus for studies.
Laser interrogators monitor the cables, and gather the information the cable ‘sensors’ provide. Biondi claims, “Every meter of optical fiber in our network acts like a sensor and costs less than a dollar to install. You will never be able to create a network using conventional seismometers with that kind of coverage, density and price.”
Optical fibers are also used to monitor pipelines and wells in the oil and gas industry. As light travels down these fibers, impurities create a backscatter signal that can be interpreted into quality information. An entire Bay Area-wide seismic network is the dream for Biondi and other scientists. The next step in the study is proving the technology can be used efficiently on an urban scale.
October 27, 2017