Refraction Seismology is a geophysical technique that uses a charge to generate energy waves traveling through subsurface structures. Which option correctly names this technique?

• A. Geophysical survey
• B. Seismic reflection
• C. Magnetic prospecting
• D. Refraction Seismology

Answer: (D)

Refraction seismology relies on how seismic waves bend as they pass from one rock layer into another. When a surface explosive source generates energy, the waves travel downward, reach interfaces where velocities change, and some energy is refracted along the boundary. These refracted waves, or head waves, then return to the surface and are recorded by detectors. The pattern of arrival times at different distances from the source lets you infer the velocities of the layers and their depths. This name specifically highlights the refraction behavior of the waves, as opposed to seismic reflection, which is based on waves reflecting back to the surface, or other methods like magnetic prospecting or broad geophysical surveys. Thus, the described technique is refraction seismology.