Weird long-period content in Mineos' displacement seismograms

Hi all,

I am running Mineos to generate synthetic seismograms for the Kaikoura earthquake. This works fine for acceleration and velocity seismograms, but introduces weird long-period signals in the displacement seismograms. The configuration of my run file are the exact same for both seismograms, which is why I cannot figure out what is going wrong. Has anyone else observed this behavior?

I can invert the curvature of the seismogram if I use different values for wmax (for example 166 instead of 200) in minos_bran, but there is no stable region where the seismogram is actually flat…

Best, Boris

With Param file given in example of mineos.pdf ,
Minos_bran < prem_noocean

Got killed after reading inputs . It created model output file but not eigenvalues functions file.

Can anyone help me in this regard ?

Thank you

Hello Boris,

I can not tell you the cause, but I do the calculations in acceleration and then I convert to displacement in my post processing. Attached is an example. Blue is specfem_globe, orange in Mineos, and green is data. Hopefully this helps.

Best,
Adam