Seismic Prospecting

Seismic prospecting has as its goal the determination of geological structure, usually in a sedimentary section. The seismic waves or pulses used arc elastic in character, at least approximately. The aim is to determine boundaries, such as interfaces between various sedimentary layers or reef edges or fault positions or other irregularities, by using the seismic waves, their reflection properties, t heir refraction properties and their scattering properties. Broadly speaking, there are two approaches, one in which the waves are stimulated by artificial explosions or mechanical devices powered in a determined way, and the other using the natural waves that occur in the earth due to ground unrest, earthquakes and the like. For seismic prospecting the latter techniques have not been very much developed, and it is the former that we shall emphasize here. Lack of present development, however, does not mean lack of future development of considerable importance. The following is a general discussion of the subject which omits much important work.