c
c        dipping layer model building program
c
c
           parameter(nx=800,nz=800)
c
           dimension vv(nx,nz)
           dimension vz(20)
c
           dimension  am(20),bm(20)
c
c          the velocity at depth is determined by line segments 
c
           nline = 8
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           bm(1) = 500.0
           bm(2) = 2000.0
           bm(3) = 3000.0
           bm(4) = 6000.0
           bm(5) = 8000.0
           bm(6) = 11000.0
           bm(7) = 14000.0
           bm(8) = 16000.0
c
c
           am(1) = -0.05
           am(2) = -0.07
           am(3) = -0.05
           am(4) = -0.05
           am(5) = +0.02
           am(6) = -0.03
           am(7) = -0.06
           am(8) = -0.00
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           vz(1) = 2000.0
           vz(2) = 2400.0
           vz(3) = 3200.0
           vz(4) = 3000.0
           vz(5) = 3500.0
           vz(6) = 3200.0
           vz(7) = 3600.0
           vz(8) = 3800.0
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           dx  = 25.0
           dz  = 25.0
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c          create initial water layer
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           do i=1,nx
            do j=1,nz
            vv(i,j) = 1500.0
            enddo
           enddo
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c          now layer by layer make velocities under each
c             line 
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c          each new layer over writes that below
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           do k=1,nline
            do i=1,nx
             do j=1,nz
             x = (i-1)*dx
             z = (j-1)*dz
             zl = am(k)*x + bm(k)
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             if( z .gt. zl ) then
               vv(i,j) = vz(k)
             endif
            enddo
           enddo
          enddo
c
c           write model to file
c
             open(16,file='dip.dat',form='unformatted')
             do j=1,nz
             write(16) (vv(i,j),i=1,nx)
             enddo
             close(16)
             end