Virtual Earthquake Technique to Forecast Los Angeles Quake Risk

Stanford University scientists are using weak vibrations generated by the Earth's oceans to produce 'virtual earthquakes' that can be used to predict the ground movement and shaking hazard to buildings from real quakes. The technique was used to confirm a prediction that Los Angeles will experience stronger-than-expected ground movement if a major quake occurs south of the city. Stanford geophysicist Marine Denolle began by installing several seismometers along the San Andreas Fault to measure ambient seismic waves. Employing data from the seismometers, the researchers then used mathematical techniques they developed to make the waves appear as if they originated deep within the Earth.