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

Hi Adam,

thank you very much for your reply. I am returning to this issue after submitting a paper on a different topic. My acceleration seismograms seem fine, with a zero trend. Which method do you recommend to integrate them?

Apart, could you provide your run script, station files and source file for Mineos with which you created the above seismograms? I want to be sure I am not using senseless parameters to generate them.

Thank you very much!

Best, Boris

Hello Boris,

I would be happy to provide you with the various scripts etc. Could you send me an email (aringler@usgs.gov) and I can put them on an ftp site or email you the pieces along with directions? I think I am using this integration method.

Best,
Adam

Hi Adam,

I have sent you an email with both my addresses. Looking forward to studying your files!

Best, Boris