Convective circulation of the mantle causes vertical deflections of Earth’s surface of up to ±2 km. As the planform of convection evolves over millions of years, the pattern of these deflections also changes, which is why we call this phenomenon `dynamic topography’.
Topography is known to play a key role in modulating Earth’s climate. From high mountains interacting with weather systems and providing sites for ice cap nucleation, through to deep ocean basins localising water currents and patterns of sedimentation. It therefore comes as no surprise that, over million-year timescales, our climate has been steadily and sometimes dramatically influenced by evolving dynamic topography.
In a paper recently published in the Annual Review of Earth and Planetary Sciences, we examine some of the links between dynamic topography and climatic events in the last ~30 million years. These include the deep-sea record of carbonate deposition and ocean circulation, inception of the Laurentide Ice Sheet, and the post-depositional vertical deflection of geological markers used to infer paleo-sea level. While there remains much work to be done, these pioneering studies lay the groundwork for exciting links between the solid Earth and paleoclimate.