Is 'crossing' vertical or horizontal?
I'm trying to imagine how one would cross a continent vertically.
Going from the Weddell to the Ross would seem to be vertical. Then again, maps are all about how you're used to looking at them.
I think crossing some type of geographic feature doesn't imply any direction. If you cross the Alps you're going north-south, but if you cross the Rockies, you're going east-west.