Geosciences Department, Stony Brook University, Stony Brook, NY 11794, USA.
Science. 2012 Feb 17;335(6070):838-43. doi: 10.1126/science.1214209.
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.
阐明板块运动的驱动力对于了解地球在其历史上的形成过程非常重要。然而，准确预测板块运动、边界带变形、刚性和应力仍然是数值模拟中的一个难题。我们提出了一个全球动力学模型，通过考虑地球顶部 200 公里内的横向粘度变化以及与地形和岩石圈结构相关的力，以及与地幔流的耦合，很好地拟合了这些参数。浅层结构与深层地幔流的相对重要性在地球表面上有所不同。我们的模型揭示了地幔流在驱动或阻碍板块运动方面的作用。此外，俯冲板块不必作为强应力导向来满足板块运动和应力的全球观测。
