Comparison of FD and FDFE for topography model:
Receivers R1 .. R13 are located on a free surface with a constant horizontal spacing of 166.66 m, the R1 receiver is on the top of the ridge. Receivers R14 .. R19 are located in depth z=615.6 m, the horizontal distance of these receivers is as follows: R14=0.0 m, R15=11.165 m, R16=166.667 m, R17=333.333 m, R18=500.0 m, R19=1000.0 m.
There are no artificial reflections arriving to any of the receivers during the defined time window. Computation was done for a series of cases with vp=2000 m/s and vs=1400 , 1000 , 750 , 500 , 300 , 200 , 0.01 m/s (the last one being just formal).
model 00 : vp=2000, vs=0.01 m/s, vp/vs= infinity ( formal ' liquid ridge ' )
model 01 : vp=2000, vs=200 m/s, vp/vs= 10
model 02 : vp=2000, vs=300 m/s, vp/vs= 6.7
model 03 : vp=2000, vs=500 m/s, vp/vs= 4
model 04 : vp=2000, vs=750 m/s, vp/vs= 2.7
model 05 : vp=2000, vs=1000 m/s, vp/vs= 2
model 06 : vp=2000, vs=1153 m/s, vp/vs= 1.73 ( =SQRT(3) )
model 07 : vp=2000, vs=1400 m/s, vp/vs= 1.42 ( This is just formal, not physical value of ratio ! )
The results of FDFE (finite-element finite-differences) hybrid method of Moczo et al. (1997) for the ridge model were kindly provided by J. Kristek (Geophys. Inst., Slovak Academy of Sciences, Bratislava, Slovakia).
The computed data, postscript figures, explanation, etc. are available free ON DEMAND
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