Scientists at the U.S. Department of Energy’s (DOE’s) Lawrence Berkeley National Laboratory (Berkeley Lab) recently determined that dark fiber—the underground network of installed, but unused fiber-optic cables across the United States and beyond—can be employed as sensors for detecting earthquakes, the presence of groundwater, changes in permafrost conditions, and other subsurface activity.
Led by researcher Jonathan Ajo-Franklin, the Berkeley team successfully combined distributed acoustic sensing (DAS) technology, which is used to measure seismic waves using fiber-optic cables, with new processing techniques to allow reliable seismic monitoring. The pairing achieved results comparable to those of conventional seismometers.
Ajo-Franklin says that dark fiber has an advantage over traditional seismometers, as these networks are nearly ubiquitous. Unlike seismometers, fiber also allows for dense spatial sampling, which could lead to early detection of earthquakes.
Click here to read the full article from Berkeley Lab, detailing the team’s research and results.
In related news, the American Society of Civil Engineers (ASCE) updated its guidance on building retrofit in earthquake zones. Seismic Evaluation and Retrofit of Existing Buildings, Standard ASCE/SEI 41-17, details deficiency-based and systematic procedures that use performance-based principles to evaluate and retrofit existing buildings to withstand the effects of earthquakes. The updated edition introduces revisions to the basic performance objectives for existing buildings and to the evaluation of force-controlled actions.
For more information, visit the ASCE website here.