[CIG-SEISMO] specfem input model

[Alejandro Gallego]

HI,
I am postdoc student at the University of Hawaii and I am trying to
use Specfem to model seismic waves in the North Atlantic ocean
I am working in an area of 20 x 30 degrees. I have two main questions.
1) Should I use Specfem_Global or Regional to work with different
mantle models.
I think the regional doesn't include a mantle model. 2) How is the
call of the function model_s20rts(   ), I am not clear what kind of
interval grid I need as an input and how can I modify this interval.
Any advice in how to change mantle model will be very helpful.

Thanks for this amaizing software

Alejandro