Climate transition at the Eocene–Oligocene influenced by bathymetric changes to the Atlantic–Arctic oceanic gateways

Abstract

Significance The 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 CO 2 concentrations and/or changes to the Southern Ocean gateways or the Tethys Seaway dominated climate changes and the inception of glaciations at the time.