Seismic methods : refraction and seismic monitoring

Abstract

Seismic methods are applied in the study of the earth’s subsurface physical characteristics. Seismic methods involve measurement of impulses generated on or below the earth surface and recorded by a receiver on the surface. The impulses which are the seismic wave are generated either artificially by an energy source such as an explosive or naturally through geological processes. Travel time of the seismic wave sent or received through a geological setting, depends on: depths of studied structures and propagation velocities of seismic waves along paths of their propagation from the source to the receiver. In seismic refraction method, the results give generalized expressions relating travel time, offset distance and velocity to thickness of subsurface layers. This is used in the determination of the thickness of layers below the surface. While in seismic monitoring, applies passive seismic methods to locate earthquakes, their distribution and their intensities. Modelling the nature and the intrinsic characteristic of the earthquakes is applied in mapping of the geological and or geothermal properties/characteristic suitable for resource exploitation.