Earthquakes detection with optical fibers

The existing optical fiber network for telecommunication, together with coherent laser interferometry techniques such as narrow-linewidth lasers and heterodyne detection, is proposed as a tool for the detection of earthquakes. Using this infrastructure, we were able to detect several earthquakes, with moment magnitude as small as 3.4 and distances to the epicenter ranging between 25 and 18500 km. Such capability is extremely relevant for the detection of earthquakes in the seas and oceans, which are today poorly covered by bulk seismometers. We propose this technique as complementary to traditional detection and show how it can be established on the existing fiber network.