I'm creating maps using the Generic Mapping Tools (GMT) from the University of Hawaii. I get weird vertical and horizontal lines using
pscoast. This is the command to reproduce the problem:
gmt pscoast -JM18c -R43/62/35/49 -G50/255/50 -Df -P > caspiansea.ps convert -density 300 caspiansea.ps caspiansea.png
The lines are already present in the ps file, so the last step (
convert) does not introduce the problem. It happens across all areas, the caspian sea area is just an example.
Version: GMT 5.2.1 (the most recent version provided by Macports) on Mac OS X 10.11.6.