Stanford Researchers Build a ‘Billion Sensors’ Earthquake Observatory with Optical Fibers

Earthquake Early Warning Systems rely on mechanical accelerometers to detect the seismic waves.  But a new approach using a particular characteristic of the fiber optic cables, which carry most of the world’s telephone and Internet traffic, is being developed at Stanford University. The system can detect vibrations that alter slightly the characteristics of the laser light shining down the fiber. An experimental pilot system has detected earthquakes ranging from ones that are local but not felt by anyone to ones that are thousands of miles away, such as the recent quakes in Mexico. Such a system would enable a global warning network to be quickly and inexpensively deployed.