Reflection seismology

Reflection seismology is a branch of seismology that uses both naturally occuring and artificially-generated seismic sources to produce images of the Earth's subsurface. By recording reflected seismic waves, and noting the time it takes for a reflection to arrive at a receiver, it is possible to estimate of the depth of the feature that generated the reflection. In this way, reflection seismology is similar to sonar and echolocation.

Reflection seismology is extensively used in exploration for hydrocarbons (i.e., petroleum and natural gas). Reflection seismology is also used for basic research into the nature and origin of the rocks making up the Earth's crust.