[CIG-SEISMO] Use of SPECFEM3D and meshfem3D for tomography

[Dimitri Komatitsch]

Dear Sergey, Dear Pieyre, Dear all,

Thank you for your message. Indeed, the manual of SPECFEM3D is obsolete
because we have an official release planned for next month and right now 
our developers are focusing on improving the last details in the code 
itself, and then at the end the manual will be updated a few days before 
the official release.

Pieyre, when you come back from the meeting in Germany could you please 
work (e.g. next week, full time) on modifying the manual to delete what 
is obsolete and include all the new things that you have added? (new 
lines in the Par_file, domain decomposition, how to check mesh quality 
and so on... how to visualize the mesh etc.). You can talk to Daniel at 
Princeton to make sure he agrees with the changes.

Sergey, the answer to your second question is that you do not need 
CUBIT, using CUBIT is easier but we also ported a simple in-house mesher 
that I developed for Southern California in this paper:

http://www.univ-pau.fr/~dkomati1/published_papers/bssa_Los_Angeles_2004_figure4_fixed.pdf

That mesher is included in the source code, and fully functional, but 
not yet described in the manual. Pieyre will add that next week.

I cc Céline Blitz as well because we should also describe in the manual 
the modifications that she made with Pieyre in that old mesher in order 
to be able to import a given velocity grid (describing for instance a 
tomographic model).

Sorry about these temporary problems; everything should be fixed (and 
the manual updated) in the next two or three weeks. I know that Daniel 
Peter and several other people at Princeton need to update the manual as 
well.

Best regards,
Dimitri.

On 09/29/2010 09:20 AM, Sergey Tikhotsky wrote:
> Dear Piere, dear Dimitri, dear all!
>
> I'm going to use the SPECFEM3D code for the purposes of seismic
> tomography at regional to local scales, including Frechet kernels
> computation and waveform inversion. I have downloaded the latest svn
> version of SPECFEM3D_SESAME and brought it to work but still have some
> questions.
>
> 1. The manual (version from august, 2010) clearly doesn't correspond to
> the actual state of the mesher meshfem3D. Thanks to your comments in
> mailing list I generally recognised the way it works, but could you
> please provide some further comments regarding the use of the new
> Par_file, particulary the relation between the "interfaces" and
> "regions" with different "materials". It looks like the borders of the
> rectangular regions may cross the interfaces. Is it correct and how it
> will be interpreted by the mesher?
>
> 2. The "Tomography model" example is based on the use of CUBIT. I don't
> have the ability to use CUBIT right now. So the first question is: "Is
> the use of CUBIT essential for the preparation of these "tomography"
> type of mesh (i.e., based on gradient or some other smooth distribution
> of properties) or the same functionality may be provided by specfem3D?".
> And if specfem3D may be used for this purpose, please give some tips on
> how it can be accomplished.
>
> Thank you in advance!
>
> Yours, Sergey.
>
>
>
>
>
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-- 
Dimitri Komatitsch - dimitri.komatitsch aT univ-pau.fr
Professor, University of Pau, Institut universitaire de France,
CNRS and INRIA Magique3D, France   http://www.univ-pau.fr/~dkomati1