[CIG-SEISMO] specfem2d external mesh

Sat Sep 26 06:34:15 PDT 2015

Hi all,

I have renamed it. Please update all your Par_files.

(the 3D codes are unchanged, only the 2D code used it)

Dimitri.

On 09/24/2015 02:40 PM, Dimitri Komatitsch wrote:
>
> Hi Phil,
>
> "enreg_surf_same_vertical" is a parameter in the DATA/Par_file that asks
> the code, if you set a receiver at a given position (x_s,z_s), to record
> at the elevation of topography z(x_s) instead of at z_s.
>
> In other words, the code ignores the value of z_s you gave and replaces
> it with the elevation of topography at this location (hence the name
> "record along the same vertical at the location of topography", which
> for some reason led to "enreg_surf_same_vertical" (surf is for
> "surface", and "enreg(istrer)" is French for "record")
>
> We should probably change that to "record_at_surface_same_vertical"
> (I initially developed the code in French, a long time ago :-)
>
> (the length is limited to 31 characters)
>
> That option is useful when one does not know the exact value of
> topography height at that location, the code will then compute it for you.
>
> Best wishes,
> Dimitri.
>
> On 09/24/2015 09:52 AM, Phil Cummins wrote:
>>
>> Hi,
>>
>> I am running specfem2d version 7.0 under Mac OS 10.9.5. We have been
>> running using a mesh generated in gmesh and converted to a specfem2d
>> using LibGmsh2Specfem_convert_Gmsh_to_Specfem2D_official.py. It was
>> working fine for our mesh but we recently tried to extend it to model an
>> earthquake source lying just outside our original mesh. Now when we try
>> to run specfem2d it produces the following output when running the
>> mesher:
>>
>>   running the mesher...
>>
>>   Reading the parameter file ...
>>
>>   Title of the simulation
>>   Basin Jakarta P-SV
>>
>>   1 1 2100.d0  500.d0   300.d0 0 0 1000.d0 100.d0 0 0 0 0 0 0
>>   2 1 2670.d0 1500.d0  1000.d0 0 0 1500.d0 500.d0 0 0 0 0 0 0
>>   3 1 3200.d0 6000.d0  3500.d0 0 0 3000.d0 800.d0 0 0 0 0 0 0
>>   4 1 3000.d0 4000.d0  2500.d0 0 0 2000.d0 600.d0 0 0 0 0 0 0
>>   5 1 3800.d0 7000.d0  4000.d0 0 0 3500.d0 1000.d0 0 0 0 0 0 0
>>
>>   Nb of solid, fluid or porous materials =            5
>>
>>   Material #           1  isotropic
>>   rho,cp,cs =    2100.0000000000000        500.00000000000000
>> 300.00000000000000        1000.0000000000000        100.00000000000000
>>   Material is solid
>>
>>   Material #           2  isotropic
>>   rho,cp,cs =    2670.0000000000000        1500.0000000000000
>> 1000.0000000000000        1500.0000000000000        500.00000000000000
>>   Material is solid
>>
>>   Material #           3  isotropic
>>   rho,cp,cs =    3200.0000000000000        6000.0000000000000
>> 3500.0000000000000        3000.0000000000000        800.00000000000000
>>   Material is solid
>>
>>   Material #           4  isotropic
>>   rho,cp,cs =    3000.0000000000000        4000.0000000000000
>> 2500.0000000000000        2000.0000000000000        600.00000000000000
>>   Material is solid
>>
>>   Material #           5  isotropic
>>   rho,cp,cs =    3800.0000000000000        7000.0000000000000
>> 4000.0000000000000        3500.0000000000000        1000.0000000000000
>>   Material is solid
>>
>>
>>   Parameter file successfully read...
>>
>>   Source           1
>>   Position xs, zs =    915000.00000000000       -20000.000000000000
>>   Frequency, delay =    5.0000000000000000        0.0000000000000000
>>   Source type (1=force, 2=explosion):            2
>>   Time function type (1=Ricker, 2=First derivative, 3=Gaussian, 4=Dirac,
>> 5=Heaviside):            3
>>   Angle of the source if force =    0.0000000000000000
>>   Mxx of the source if moment tensor =    1.0000000000000000
>>   Mzz of the source if moment tensor =    1.0000000000000000
>>   Mxz of the source if moment tensor =    1.0000000000000000
>>   Multiplying factor =    10000000000.000000
>>
>>
>>   The mesh contains       160167  elements
>>
>>   Control elements have            4  nodes
>>
>>
>>   Min and max value of X in the grid =    750000.00000000000
>> 1000000.0000000000
>>   Min and max value of Z in the grid =   -150000.00000000000
>> 1474.3499999999999
>>
>>   nedges_coupled (acoustic/elastic)           0
>>   nedges_coupled (acoustic/poroelastic)           0
>>   nedges_coupled (poroelastic/elastic)           0
>>
>>   Position (x,z) of the source =    915000.00000000000
>> -20000.000000000000
>>
>> STOP for now we cannot use both enreg_surf_same_vertical and
>> read_external_mesh
>>
>>    running the solver...
>>
>> We suspect the "STOP" message is indicating some problem with the mesh,
>> but we don't know what "enreg_surf_same_vertical " is referring to. Can
>> someone please tell us what this means?
>>
>> The specfem2d solver tries to run anyway, but eventually hits a floating
>> point exception after printing out the total number of receivers.
>>
>> No doubt we have made some mistake with our external mesh, but it is
>> difficult to diagnose the problem. Do you think this
>> "enreg_surf_same_vertical " message is telling us what the problem is,
>> and if so what does it mean?
>>
>> Thanks,
>>
>> - Phil
>> ------------------------------------------------------------------------
>>
>>
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>>
>

-- 
Dimitri Komatitsch
CNRS Research Director (DR CNRS), Laboratory of Mechanics and Acoustics,
UPR 7051, Marseille, France    http://komatitsch.free.fr