Hi,everyone!

I would like to output the fluid displace and solid displace at the same time,in an isotropic poroelastic.In DATA/Par_file,set parameters about receivers,the seismotype just have six record,1=displ 2=veloc 3=accel 4=pressure 5=curl of displ 6=the fluid potential.It is missing the parameters i want–the fluid displace.How can i output this parameter?

Thanks and Kind Regards,

jun li

by default, the displacement/velocity/acceleration from a station within a poroelastic element will be coming from the solid wavefield part (displs_poroelastic/…), the fluid displacement (displw_poroelastic/…) is not output and implemented yet.

the easiest would be you change the code line with the corresponding wavefield you want in file src/specfem2D/write_seismograms.F90, see:

Thank you very much for your answer.i will try your suggestion to modify write_seismograms.F90.

Best wishes,

Jun li

Hi,

i modify write_seismograms.f90,then i output the fluid displace.

i just modify case (1)

! displacement

call compute_vector_one_element

(potential_acoustic,displ_elastic,displs_poroelastic,ispec,vector_field_element)

modify displs_poroelastic to displw_poroelastic.then i calculate one example,the result of the calculation seems to be wrong.

according to Biot’s theroy,the fast P waves in the solid and fluid,their phase is same. the slow P waves in the solid and fluid,their phase is opposite.However,the actual calculation result is not like this.I compared the calculation results of the half-space with the theoretical results and found that the solid displacement results correspond well, and the fast P waves of the fluid displacement are in opposite phase to the theoretical ones, and their amplitudes are also very small.The following is a comparison between my results and theoretical results，

our parameters are somewhat different, but the biggest problem is that the waveforms do not completely correspond.

I have calculated the response of single-layer and two-layer porous media. The solid phase displacement and velocity parameters are all correct. Therefore, I think the program should be correct. However, I only changed one output and the fluid displacement was wrong.

I hope you can give some advice,any advice is greatly appreciated.

Thanks for your help.

jun li