RT Journal Article SR Electronic T1 Plate Motions and Stresses from Global Dynamic Models JF Science JO Science FD American Association for the Advancement of Science SP 838 OP 843 DO 10.1126/science.1214209 VO 335 IS 6070 A1 Ghosh, Attreyee A1 Holt, William E. YR 2012 UL http://science.sciencemag.org/content/335/6070/838.abstract AB Delineating the driving forces behind plate motions is important for understanding the processes that have shaped Earth throughout its history. However, the accurate prediction of plate motions, boundary-zone deformation, rigidity, and stresses remains a difficult frontier in numerical modeling. We present a global dynamic model that produces a good fit to such parameters by accounting for lateral viscosity variations in the top 200 kilometers of Earth, together with forces associated with topography and lithosphere structure, as well as coupling with mantle flow. The relative importance of shallow structure versus deeper mantle flow varies over Earth’s surface. Our model reveals where mantle flow contributes toward driving or resisting plate motions. Furthermore, subducted slabs need not act as strong stress guides to satisfy global observations of plate motions and stress.