-
oa Viscoelastic Finite-difference Modeling with Application to Shallow Seismic Refraction Data
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, The 4th International Symposium on Recent Advances in Exploration Geophysics (RAEG 1999), Dec 1999, cp-420-00004
Abstract
I have developed a two-dimensional, viscoelastic, finite-difference modeling method for complex surface topography and subsurface geological structure. Realistic modeling of seismic wave propagation in the near surface is complicated by many factors, such as strong heterogeneity, topographic relief and large attenuation. In order to account for these complications, I use a velocity-stress staggered grid and employ an O(2,4) accurate viscoelastic finite-difference scheme. The implementation includes an irregular free surface condition for topographic relief. The algorithm is applied to 2-D modeling of the viscoelastic response of near surface structure beneath a 2-D refraction survey line. The P-velocity models were constructed by 2-D traveltime tomography, and S-velocity, density and Q were given empirically. Comparison of the observed waveform data with viscoelastic response clearly demonstrates the importance of inclusion of viscoelasticity. The character of the observed waveform data can be explained by velocities and Q distributions.