Program halfsp

The basic computation is for a Rayleigh wave in a half-space medium. The motion-stress vectors for this type of problem are easily computed with the BSU program halfsp. Man pages for this program can be viewed in an x-term with the command,

man halfsp

This program is very basic with only a man page for documentation. The output is a text file listing the half-space properties at the top followed by 4 columns of the motion stress vector values with depth. To read more on this topic, see Aki and Richards ((1), chapter 7). The program is run from an x-terminal with a single command:

halsfp

The user is then prompted for the half-space properties (density, P-velocity, S-velocity), and the depth sampling for the motion-stress vector computations. A typical dialog is as follows:

pm@penguin: halfsp
ENTER RHO,VP,VS
1600,800,100
ENTER FREQ,NZ,Z0,ZEND
40,50,0,20
PHASE VEL= 95.4331

This produces a file, halfsp.tmp, a portion of which is shown below:

   HALFSP.F OUTPUT:
  RHO=0.1600E+04
  MU=0.1600E+08
  LAME=0.9920E+09
  FREQ=0.4000E+02
  P-WAVE VELOCITY=0.8000E+03
  S-WAVE VELOCITY=0.1000E+03
  RAYLEIGH WAVE PHASE VEL=   95.4331
 R1=Horiz. Displacement R2=Vertical Displacement
 R3=Horiz. Stress       R4=Vertical Stress


     DEPTH      R1         R2         R3         R4

       0.0  0.120E+01  -.219E+01  0.804E+02  0.000E+00
       0.4  -.122E+00  -.259E+01  0.834E+08  0.458E+08
       0.8  -.439E+00  -.224E+01  0.902E+08  0.495E+08
       1.2  -.444E+00  -.175E+01  0.762E+08  0.418E+08
       1.6  -.367E+00  -.132E+01  0.592E+08  0.325E+08
       2.0  -.283E+00  -.981E+00  0.445E+08  0.244E+08
       2.4  -.212E+00  -.722E+00  0.329E+08  0.181E+08
       2.8  -.157E+00  -.529E+00  0.242E+08  0.133E+08
       3.2  -.115E+00  -.387E+00  0.177E+08  0.972E+07
       3.6  -.842E-01  -.282E+00  0.130E+08  0.711E+07
       4.0  -.616E-01  -.206E+00  0.946E+07  0.519E+07
       4.4  -.450E-01  -.151E+00  0.691E+07  0.379E+07
       4.8  -.328E-01  -.110E+00  0.505E+07  0.277E+07
       5.2  -.240E-01  -.803E-01  0.368E+07  0.202E+07
       5.6  -.175E-01  -.586E-01  0.269E+07  0.148E+07
       6.0  -.128E-01  -.428E-01  0.196E+07  0.108E+07
       6.4  -.933E-02  -.312E-01  0.143E+07  0.786E+06
       6.8  -.681E-02  -.228E-01  0.105E+07  0.574E+06
       7.2  -.497E-02  -.166E-01  0.764E+06  0.419E+06
       7.6  -.363E-02  -.121E-01  0.558E+06  0.306E+06
       8.0  -.265E-02  -.887E-02  0.407E+06  0.223E+06
       .
       .
       .
      18.0  -.101E-05  -.340E-05  0.156E+03  0.855E+02
      18.4  -.740E-06  -.248E-05  0.114E+03  0.624E+02
      18.8  -.541E-06  -.181E-05  0.830E+02  0.456E+02
      19.2  -.395E-06  -.132E-05  0.606E+02  0.333E+02
      19.6  -.288E-06  -.964E-06  0.443E+02  0.243E+02
      20.0  -.210E-06  -.704E-06  0.323E+02  0.177E+02