Detecting ocean-floor seismic activity is crucial to our understanding of the interior structure and dynamic behavior of the Earth. However, with 70% of the planet’s surface covered by water and only a handful of permanent, ocean-bottom seismometer stations, very little overall seismic activity is actually recorded.
Now, a group of researchers from the United Kingdom, Italy and Malta have found a way to use submarine fiber optic cables already deployed on the ocean floor as seismic detectors. In a paper published in the journal Science, the research group outlines how they discovered this capability and how it would operate.
Giuseppe Marra, a member of the group, was testing an underground fiber cable between two locations in the United Kingdom. Noticing a small slowdown in signal delivery, he traced it to tiny vibrations bending the light. He then determined that the vibrations were caused by a remote earthquake. This discovery inspired him to explore using fiber optic cables as seismic detectors.