When
Douglas MacAyeal at the University of Chicago gave undergraduate science
interns the boring task of digitizing satellite photos of Antarctic lakes,
little did he know that he would stumble upon a neat geographical curiosity:
the lakes don’t stay put – in fact, they
move rapidly along the coastline.
MacAyeal thinks the explanation lies in the unusual location of
the George VI ice shelf, trapped as it is in a narrow channel between
Alexander Island and the Antarctic mainland. As the ice sheet squeezes
through the channel, its outer edges buckle into a series of crests
and troughs. The lakes sit in the troughs. The ice shelf pushes into
Alexander Island at an oblique angle, so the end of each trough tracks
along the coast, dragging its lake with it.