Estimation of Q Value in Formations

SYNOPSIS There are two factors which govern the rate of amplitude decrease during propagation of seismic waves through isotropic and homogenous media. The first is attenuation due to geometrical expansion of the wave front. The second is attenuation due to energy loss from the non-linear deformation of the media of propagation. This factor is called “Q value”. In addition to P and S wave velocities and density of formations, Q value is a very important quantity which governs ground behavior during earthquakes. This paper presents some aspects of Q value. It is based on in-situ geophysical measurements and the results of analysis.