Produce the surface map. The CONSTANT= option specifies a value that is less than the default value so the spikes are narrower at the base. The NLINES= option specifies the maximum number of map lines, which gives the best map shape resolution. The ROTATE= and TILT= options adjust the map orientation to make the crowded spikes in the northeast portion of the map easier to distinguish.

proc gmap map=maps.europe data=sashelp.demographics;
   id id;
   surface pop / constant=4
                 nlines=100
                 rotate=40
                 tilt=60;
run;
quit;