A New Experiment Transforms Optic Cables into Seismographs

Lori Dengler, emeritus professor of geology at Cal Poly Humboldt, recently reported on an experiment that has temporarily turned a section of underground optic cable between Arcata and Eureka, California, into a seismic experiment.

The cable, which is part of a local broadband improvement project, is offline until the rest of the system is completed. While the cable is dark, researchers have attached to it a Distributed Acoustic Sensing (DAS) instrument. This uses the cable as a conduit for a rapid series of laser pulses that in effect allow it to function like a string of seismographs. Deployed alongside the cable are broadband seismographs and geophones that will help researchers understand how to interpret the data that they collect from the DAS instrument. The results of this experiment could help pave the way toward one day using trans-Pacific optic cables to help detect and study seismic activity.

Learn more: Read Lori Dengler’s column in the Times Standard.

Read more about how the experiment came into being: Running a seismic experiment requires a public-private partnership.