What I’m about to say might sound crazy, but I think a lot of geologic observations are about seeing lines. Lines on a graph, lines in the rocks, lines in the landscape, lines in flow circulation, and they all tell you something. The link below contains an image of bathymetry (ocean floor topography, blues are deep water, reds are more shallow water areas) in the Arctic Ocean north of Russia. The recent, high-resolution mapping shows amazing glacial lineations, where an overriding ice sheet scratched into the soft marine sediment. Gorgeous!