[CIG-SEISMO] specfem2D vertical incidence of planar waves

[Dimitri Komatitsch]

Dear Giuseppe,

You probably simply forgot to set

add_Bielak_conditions           = .true.,

which is needed to combine plane waves with absorbing boundaries.
(I am not sure if we say it in the manual; I will check tomorrow and add 
it if needed).

Best regards,
Dimitri.

On 10/08/2012 04:57 PM, giuseppe.digiulio at ingv.it wrote:
> Dear users of SPECFEM,
>
> I am looking to run specfem2d with a vertical incident plane wave. My
> 2D model is very simple (3 uniform layers) based on an external mesh
> (by means of gmsh).
>
> I propagated P waves (source_type 1) but I noted strange boundary
> effects starting from the left and right sides of my model (see the
> vector displacement field in the *ps files). These effects produce
> strong interferences  on the *BHX* component, and  my receivers
> (situated at the surface) show a  *BHX* component comparable to *BHZ*
> component in amplitude.
>
> The same disturbance happens using a SV wave as input (in this case a
> P component soon arises from the left and right sides of the model).
> Likely I wrong something. Hints aimed to simulate a vertically
> incident wave in 2D models are welcome.
>
> Thanks in advance
>
>
> Regards,
> Giuseppe Di Giulio
>
> PS: I attach some input files
> ----------------------------------------------------------------
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-- 
Dimitri Komatitsch
CNRS Research Director (DR CNRS), Laboratory of Mechanics and Acoustics,
UPR 7051, Marseille, France    http://komatitsch.free.fr