The movement of carbon between the atmosphere, oceans and continents—the carbon cycle—is a fundamental process that regulates Earth's climate. Some factors, like volcanic eruptions or human activity, emit carbon dioxide into the atmosphere. Others, such as forests and oceans, absorb that CO2. In a well-regulated system, the right amount of CO2 is emitted and absorbed to maintain a healthy climate. Carbon sequestration is one tactic in the current battle against climate change.

The work is published in the journal Proceedings of the National Academy of Sciences.

“We were able to show, for the first time, that the shape and depth of the ocean floor play major roles in the long-term carbon cycle,” said Matthew Bogumil, …

The long-term carbon cycle has a lot of moving parts, all functioning on different time scales. One of those parts is seafloor bathymetry—the mean depth and shape of the ocean floor. This is, in turn, controlled by the relative positions of the continent and the oceans, sea level, as well as the flow within Earth’s mantle. Carbon cycle models calibrated with paleoclimate datasets form the basis for scientists’ understanding of the global marine carbon cycle and how it responds to natural perturbations.

“Typically, carbon cycle models over Earth’s history consider seafloor bathymetry as either a fixed or a secondary factor,” said Tushar Mittal, the paper’s co-author and a professor of geosciences at Pennsylvania State University.

…