Long-term global sea-level change due to dynamic topography since 410 Ma

Abstract

Sedimentary studies at continental boundary show that the global sea level has hundreds of meters of change since the late Paleozoic. Long-term global sea-level change is closely related to the mantle convection. The deflection of the ocean basins caused by dynamic topography can change the container volume of the basin, thus inducing global sea-level change. However, the influence of dynamic topography on the global sea-level change during supercontinent cycles is not well understood. Based on dynamic topography from mantle convection models and past seafloor age from plate reconstructions, I studied the influence of dynamic topography on global sea-level change since 410 Ma. Model results show that the present-day dynamic topography contributes to ∼120 m of positive global sea level. Dynamic topography raises the sea level during the dispersal, assembly, and transition phases, and drops the sea level during period of supercontinent stability. Global sea-level change caused by the seafloor age distribution is the main factor that controls the long-term global sea-level change. Different methods to define the ocean basin have only a small influence on global sea level change due to the combined effects of seafloor age and dynamic topography. The combined effects of dynamic topography and seafloor age uplift the sea-level during Pangea dispersal and assembly phases, and decrease sea-level during stability and the transition phases.