LAUSR

SignificanceThe results show that dynamic variations in the Earth's interior could have played a key role in the Eocene-Oligocene climatic transition (∼33.9 Ma) and the inception of glaciations. Pulsations in the Iceland mantle plume modified the bathymetry of the Greenland-Scotland Ridge, which affected deep water formation in the North Atlantic. Our model simulations show that the changes in the Atlantic-Arctic oceanic gateways cooled the Southern Hemisphere, and later the Northern Hemisphere, paving the way for the growth of major land-based ice sheets. This supplements the current view that decreasing atmospheric CO2 concentrations and/or changes to the Southern Ocean gateways or the Tethys Seaway dominated climate changes and the inception of glaciations at the time.