Straight line ground features. Russia-Mongolia
I fly the N. Europe - Tokyo route (across the Russian tundra and down across the Mongolian plateau fairly frequently) and have always been puzzled by the many straight line ground features. And when I say straight I mean ruler straight. They're more easily detectable in the winter when the ground is frozen solid with snow & ice.
I thought at first that they might be tracks created by the nomadic movements of people but since they are straight lines for many tens of miles at a time, never deviating around obvious rises and falls in the ground they don't somehow seem natural. I would imagine man-made trails would divert around hills and mountains for efficiency, but these just go on and on straight across frozen rivers up hill and down dale and only changing direction abruptly and occasionally.
Presumably others have seen these, and I find them endlessly fascinating. Has anyone any ideas about precisely what they are and how they are caused?