The Seismological Society of America hosted a briefing on June 17 on fiber optic analyses, proving that using fiber optic analyses could be instrumental to the maintenance and safety of America’s infrastructure. Panelists included Herb Wang from the University of Wisconsin- Madison and Nate Lindsay from the University of California, Berkley, and they focused on how these cables do more than just provide speedy internet.
How It Works
According to Wang and Lindsay, the cables that bring us speedy internet connections have the potential to become world’s largest seismograph through a process called distributed acoustic sensing (DAS). The benefit of this? Seismologists can gather data from practically the entire length of a fiber optic cable, giving multiple reference points to better determine the location of seismic events. This creates an almost real-time picture of what is happening both above and below the ground. With U.S. Infrastructure, it can do the following: infrastructure: permafrost repairs, seismology, and road Maintenance.
Permafrost Repairs
Permafrost is soil and groundwater and is often found at high latitudes, which remains at below-freezing temperatures throughout the year. According to the 2017 Report Card for Alaska’s Infrastructure, swathes of permafrost in rural Alaska and the Arctic Circle are now thawing in the summer heat, posing a danger to the roads, rail, and particularly airport runways. This can significantly damage the infrastructure of these regions if left untreated. DAS has the potential to detect the stress of long-term deformation in the melting permafrost, allowing engineers to repair and strengthen the roads before emergency repairs are warranted.
Seismology
The most direct application for fiber optic seismology is seismology. The innovation lies in integration into the existing internet fiber optic infrastructure. With the installation of new projects, such as offshore wind farms on the west coast, seismologists could create points of seismic data collection along the fiber optic cable, which would have been impractical or less effective with conventional seismographs. This could grant seismologists the ability to analyze and predict the effect of deep-sea earthquakes on coastal regions much more quickly and effectively, giving both an early warning to coastal areas of offshore earthquakes and allowing engineers to prepare future infrastructure projects (such as drilling or wind power platforms) the risk posed by undiscovered fault lines.
Road Maintenance
DAS can detect relatively minute differences in ground vibration, and can determine the speed, weight, and severity of traffic on the road, bridge, or railway where it is installed—revolutionizing how infrastructure maintenance is conducted and acting as the key to achieving a model of resilient infrastructure. An affordable means of detecting vibrations—the cost of digging and laying cables— future road construction
