Origin of Ice Ages: an Ice Shelf Theory for Pleistocene Glaciation

Abstract

A RECENT paper by Wilson¹ suggests that ‘thermal’ surges of the Antarctic ice sheet led to the growth of large ice shelves in the Southern Ocean, and that these shelves cooled the Earth sufficiently to cause glaciations in the northern hemisphere. That the southern hemisphere may dominate the northern in this way is the antithesis of a suggestion in an earlier paper² by me. However, both that paper² and a later one³ do discuss the possibility of large thermal surges in Antarctica (see especially ref. 2, 185; ref. 3, 312), and since these papers were published I have been examining the further possibility that the surges act as ‘triggers’ for northern glaciation. The theoretical results of this examination, which will be published elsewhere, are inconclusive: the ice shelf theory for glaciation involves so many glaciological, oceancgraphical and meteorological assumptions that it may be impossible to justify all of them. It is the purpose of this communication to suggest how field evidence may be used to test the theory. Really convincing tests will probably require contributions from field workers in every part of the world.