(DOE/Lawrence Berkeley National Laboratory) Researchers at Berkeley Lab have turned parts of a 13,000-mile-long testbed of ‘dark fiber’, unused fiber-optic cable, owned by the DOE Energy Sciences Network (ESnet) into a highly sensitive seismic activity sensor that could potentially augment the performance of earthquake early warning systems currently being developed in the western United States.

Original source: https://www.eurekalert.org/pub_releases/2019-02/dbnl-dfl020519.php