Put topo and any other grid on a same plot

Dear All,

I tried to plot the second invariant of the strain rate tensor by using a related NetCDF grid. However, I also want to put the topography just for the background (colorless). I do not use any cpt for the topo grid. Should I use it? If yes, it seems that it should be done a bit tricky.
I was not able to carry out it anyway. As far as I understand in the figure on attach (coming from Sandwell and Wessel 2016) it could be done. Do you have any suggestions for me? (Especially by Dr. Wessel :slight_smile:)

Thank you for your all help.

Have a nice day.

Those types of maps are done with grdimage using your strain grid as the main grid input but then you derive a gradient grid from topography using grdgradient and pass it via -I on the grdimage command line.

Now, the case is solved.

Thank you for your all help.