STRESS-INDUCED SEISMIC REFLECTION

DICKSON, W., 4509 Drexel Dr., Raleigh, NC 27609, dicksonb@nc.rr.com.

The acoustic impedance of a stress-induced acoustic reflector is considered. The two media reflection problem is presented for the case where the density is constant across a stress boundary. The reflection coefficient is found to depend only on the wave velocities in the stressed and unstressed regions. The shear and elastic moduli are found to equal the square of the wave velocity multiplied by the density. This allows the modulus of elasticity (Young's modulus) and the shear modulus to be calculated directly from the seismic reflection characteristics. Variations in the elastic modulus are shown to be sufficient to generate seismic reflections from a region of otherwise constant density and wave velocity.