Glacial Cycles drive varitions in the production of oceanic crust

Abstract

Glacial cycles redisturibute water beteen oceans and continents, causing pressure changes in the upper mantle, with consequences for the melting of Earth's interior. Using Plio-Pleistocene sea-level variations as a forcing function, theoritical models of mi-ocean ridge dynamics that include melt transport predict temproal variations in crustal thickness of hundreds of meters. New bathymetry from the Australian-Antarctic ridge shows statistically significant spectral energy near Milankovitch periods of 23, 41, and 100 thousand years, which is constistent with model predictions. These results suggest that abyssal hills, one of the most common bathymetric features on Earth, record the magmatic response to changes in sea level. The model and data support a link between glacial cycle at the surface and mantle melting at depth, recorded in the bathymetric fabric of the sea floor.