Ambient Noise Tomography

Recent advances in seismic methods use coherent signals recorded at pairs of stations to image the underlying structure without relying on earthquakes or explosions. This low-amplitude seismic "noise," present at all seismic stations, comes from various sources, including waves and wind along shorelines, and local, man-made activities like cars, trucks, and trains. Known as "Ambient Noise," it can be cross-correlated over long time series between stations to retrieve the common signal, filtering out incoherent energy and revealing seismic velocity information between two seismometers. This process, called Ambient Noise Tomography (ANT), uses an array of stations to determine a three-dimensional image of subsurface shear velocity.

Ambient Noise Tomography offers new possibilities for imaging the subsurface at various scales and complements traditional passive source tomography, enabling seismic imaging without earthquakes. ISTI seismologists are experts in using ANT to decipher the subsurface velocity structure beneath your region of interest. Contact us today for a quote.

The slideshow includes the workflow for ANT data processing.