The fiber-optic cables that travel underground, along the seafloor and into our homes have potential besides transmitting videos, emails and tweets. These signals can also record ground vibrations as small as a nanometer anywhere the cable touches the ground. This unintended use for fiber-optic cables was discovered decades ago and has had limited use in military and commercial applications.
A University of Washington pilot project is exploring the use of fiber-optic sensing for seismology, glaciology, and even urban monitoring. Funded in part with a $473,000 grant from the M.J. Murdock Charitable Trust, a nonprofit based in Vancouver, Washington, the new UW Photonic Sensing Facility has three decoder machines, or “interrogators,” that use photons traveling through a fiber-optic cable to detect ground motions as small as 1 nanometer.
“Fiber-optic sensing is the biggest advance in ground-based geophysics since the field went digital in the 1970s,” said principal investigator Brad Lipovsky, a UW assistant professor of Earth and space sciences. “The UW Photonic Sensing Facility and its partners will explore this technology’s potential across scientific fields — including seismology, glaciology, oceanography and monitoring hydrology and infrastructure.”
“We’re getting to the ‘smart Earth’ concept, where we can listen to the Earth,” said Marine Denolle, a UW assistant professor of Earth and space sciences. “This technology allows seismic sensing to go to places you could not go before — where it was too hard, or too expensive, to deploy sensors. The other aspect that’s new is a density of sensors beyond what we had before.”
Read more at UW News »