## INRIA bench-mark versions of the Marmousi model

**Ludek Klimes**
Two smooth continuous bench-mark 2-D models without structural
interfaces, based on the Marmousi model,
have been prepared for the workshop
"Computation of multi-valued traveltimes" held
in INRIA Rocquencourt, France, on September 16-18, 1996.
The ** "hard" model ** is globally quite rough
and is smooth on the scales of the order of several metres.
Let us point out once again that the "hard" model
is a continuous model without interfaces.
The ** "smooth" model ** is a considerably smoothed
version of the "hard" model.

The slowness in both smooth models without interfaces
is interpolated by natural bicubic
splines in the regular grid of 122 points vertically times
384 points horizontally. The grid spacing is 0.024km in both
directions. The size of the spline grid is thus
2.904km vertically and 9.192km horizontally.
The grid velocities in m/s are stored with the inner loop from the top
to the bottom and the outer loop from the left to the right.

The figures below display the velocities in the centres of the
square cells formed by the gridlines of the given B-spline grid.
Corresponding PostScript figures may be calculated by history file
mar-grd.h.

### "Hard" Marmousi model

### "Smooth" Marmousi model

### Reference

Bulant, P. & Klimes, L. (1996):
Examples of seismic models. Part 2.
Seismic Waves in Complex 3-D Structures, Report 4,
pp. 39-52, Dep. Geophys., Charles Univ., Prague .