| Popis: |
Synthetic seismic response of a realistic model representing Deccan flood basalt was computed following elastic and viscoelastic formulation of wave propagation. The model was prepared by using measured data on core samples, obtained from KLR-1 borehole (18 03’ 07’’ N, 76 33’ 20’’ E), drilled at Killari in Deccan Volcanic Province of western India. Drilling results from KLR-1 borehole indicate that in Killari, a thin layer of sediments exists, which cannot be resolved seismically. Laboratory results indicate that there exists appreciable velocity contrast between different layers of basalts. We also observed differences in attenuation values in different layers of basalt. This makes, Deccan basalts, a motivating case for viscoelastic formulation of seismic wave propagation. In this paper we attempt to address the effect of velocity contrast and attenuation on seismic modeling by simulating the wave propagation in Deccan basalt, following viscoelastic formulations. We show that, the seismic waves are highly attenuated in the viscoelastic media, with slight velocity dispersion as compared to the elastic media. We can also infer that the viscoelastic formulations with three relaxation mechanisms (i.e. L=3) can better incorporate Q. |
