Sample computations in the model 98

Petr Bulant & Ludek Klimes

The sample synthetic model named "98" was created during the technical session of the SW3D consortium meeting in June 1998. The aim of the work done was not to create a realistic model, but to demonstrate capabilities of program packages MODEL and CRT. The participants of the meeting were asked how should the model look like and which computations should be performed. The data and MS-DOS batch files for the computations were prepared just during the session. It was thus a good opportunity to learn a lot about both the program packages. History files to manage the computations using Perl were added later.

History file 98-mod.h may be used to display the structural interfaces and P-wave velocities in the model in the Virtual Reality Modeling Language (VRML).

File 98-srf.wrl contains 3-D view of the structural interfaces in the model. The interfaces are coloured according to indices of the surfaces covering them.

File 98-vp.wrl contains 3-D view of the "solid" P-wave model, composed of several P-wave velocity sections.

History file 98-ss.h, calculating synthetic seismograms, also generates file 98-ray.wrl containing 3-D VRML representation of the corresponding 2-point rays.


The model 98 is composed of three layers separated by two interfaces. The upper interface is curved, the lower one is formed by dipping plane. A salt body in the middle layer is bounded by spherical interface. Here you can see the 3-D picture of the model (14 kB). Look also at the description 98-mod.htm of the data file 98-mod.dat, which is an input data file for the MODEL package. The file 98-mod.dat was prepared by manually editing file len-mod.dat.


Following computations were managed by history files.

Travel-time computation

Seismogram generation

Table of the history files, data files, executables and resulting figures

History file: Data files: Executables needed: Resulting figures:
Computation of P and S wave velocity cross-sections: 
98-grd.h 98-mod.dat grdps 98-vel?.ps
Generation of VRML files: 
98-mod.h 98-mod.dat iniwrl 98-srf.wrl
98-cam1.dat modsrf 98-vp.wrl
98-cam2.dat trgl
98-dli1.dat srfwrl
98-dli2.dat bndlin
hsv.dat linwrl
Travel-time computation:
98-mtt.h 98-crt1.dat crt 98-tt0??.ps
98-mod.dat grdps 98-tt1??.ps
98-rec.dat mgrd
codep.dat mtt
98-src.dat mttgrd
Synthetic seismograms generation: 
98-ss.h 98-crt2.dat crt 98-sst?.ps
98-mod.dat green 98-ssf?.ps
98-rec.dat greenss 98-ssb?.ps
98-rpa2.dat sp 98-sse?.ps
98-src.dat ss 98-ray.wrl