'COMPLEX BLOCK' 1 'VP ' 1 (P wave velocity) 1 2 3 (0) (i.e. 3-D grid VP=VP(X1,X2,X3), tension ignored) 4 3 3 (numbers of grid points) 0 20 40 60 (X1 grid coordinates) -20 0 20 (X2 grid coordinates) 0 -10 -20 (X3 grid coordinates) 4. 4. 4. 4. 4. 4. 4. 4. 4. 4. 4. 4. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 5. 6. 6. 6. 6. 6. 6. 6. 6. 6. 6. 6. 6. ========================================================================