In the seismic refraction method, seismic waves are recorded that propagate along layer boundaries or as arcuate "diving waves" mainly sub-horizontally. The seismic signals, produced by controlled seismic sources, are recorded along lines of seismometers deployed on land or in the ocean (ocean-bottom seismometers). Although this method can also be used in engineering geology for near-surface investigations, we apply it to analyze deep crustal structures, the crust-mantle boundary and the uppermost mantle. |