SEISMIC ENERGY

Seismic reflection reminder Seismic energy is reflected (echoed) from interfaces as well as transmitted. Strength of reflection depends on Seismic speed contrast across interface Density contrast across interface Transmitted energy can be partially reflected by still-deeper interfaces Seismic Reflection Travel-time, strength of "echoes" from layers below source measured Travel-times give relative depth Strength gives property contrast Repeated at close spacings along profile (compare echo-sounder) Result is seismic section, which mimics layer distribution in subsurface Basic …

…geophysics, reflection refers to the seismic energy or signal that returns from an interface of contrasting acoustic impedance, known as a reflector, according to Snell's law. Reflection seismic surveys are useful for mapping geologic structures in the subsurface, interpreting sedimentary environments and evaluating hydrocarbon accumulations that might occur as amplitude anomalies. Reflection surveys are complicated by the variation of velocity as well as the various types of wave energy that are propagated within the Earth.