Plate tectonic theory was extremely successful in providing a framework for understanding deformation and volcanism at plate boundaries, and allowed us to understand how continent motions through time are a natural result of heat escaping from Earth's deep interior. Plate tectonics also provided a scientific framework for earthquake and volcanic hazard assessment and hydrocarbon exploration. Plate tectonics is, however, an incomplete theory: For instance, we lack a generally accepted mechanism that explains plate tectonics in the framework of mantle convection, and the origin of intra-plate volcanism such as hotspots and Large Igneous Provinces are controversial. Commonly, a deep mantle plume origin is assumed, but alternative models exist.

Linking surface and lithospheric processes to the mantle is extremely challenging and is only now becoming feasible due to better constraints on deriving ancient longitudes before the Cretaceous, much improved seismic tomographic images, better understanding of the dynamics of true polar wander and recent advances in mineral physics. Dramatic improvement in computational capacity and numerical methods that efficiently model mantle flow while incorporating surface tectonics, plumes, and subduction, have emerged to facilitate further study, and the principal CAS objectives was to (1) Develop a Global Subduction Absolute Reference Frame, and (2) Link Surface and Deep Processes.

The stay at CAS was extremely rewarding both scientifically and socially. The value of bringing together focused top-notch scientist for almost a year cannot be emphasized enough, and CAS is not only unique to Norway, but to the world. The achieved results are far beyond our original expectations: As just one example, we had planned to develop a fully dynamic Earth model for the past 300 million years, but managed to extend this to the past 550 million years. Our results have already been published in a few articles, and presented at international meeting; but the bulk of our results will be published over the coming 1-2 years. CAS also stimulated the Group Leader along with most CAS Fellows to write a Norwegian Centre of Excellence Application (SFF-III), and if successfully funded in 2013, will carry the important work at CAS onwards for the next decade.

Over the last century our description of the movement and deformation of the Earth's outer layer evolved from the hypothesis of Continental Drift into Sea-Floor Spreading and thence to the theory of Plate Tectonics. Now a fourth revolution is underway in which Plate Tectonics is being subsumed into the new framework of Mantle Dynamics, the title of our CAS project. Scientists in Norway were hardly involved in the development of the first three revolutions in Earth Sciences, but through CAS, we are confident that Norway has made key and long-lasting contributions to Mantle Dynamics and to our understanding of the Dynamic Earth.