In 1928, the airship Graf Zeppelin flew over the
Arctic to reveal:
the truly bizarre landscape of the polar
world. In some areas there were flat plains
stretching from horizon to horizon that were
dotted with innumerable and inexplicable
lakes. In other regions, linear gashes up to a
mile or more long intersected to form giant
polygonal net works. This bird’s-eye view
confirmed what were then only incidental
surface impressions that unglaciated polar
environments were very unusual.
(Butzer 1976, 336)