Using Geology to Constrain the Role of Plate Bounding Forces in Geodynamic Models of Mantle Convection with Plates

[901477]最近的地幔对流模型表明，板块运动的历史可以部分地用板块与地幔对流的耦合来描述，这种耦合是由先前俯冲的板块驱动的。由于板块在地幔中的分布变化缓慢，板块运动的变化发生在几百万年的时间尺度上，一定是由于板块-地幔系统的某些其他动力成分。PI将研究可能发生在俯冲带和转换断层的板块束缚力的作用。包含这些力的地幔对流模型应该能够预测板块速度、动态应力和地幔密度分布的变化。这些预测可以用地质观测数据进行检验，比如板块运动的历史、应力历史和隆起的观测以及地震层析成像，并且应该限制板块束缚力在地幔对流和板块构造动力学中的作用。

9901477ConradRecent models of mantle convection show that the history of plate motions can be partly described by the coupling of plates to mantle convection driven by previously subducted slabs. Because the distribution of slabs in the mantle changes only slowly, changes in plate motion that occur on time scales of a few million years must be due to some other dynamical component of the plate-mantle system. The PI will investigate the role of plate bounding forces that may occur at subduction zones and transform faults. Models of mantle convection that include such forces should yield predictions of changes in plate velocity, dynamic stresses, and the distribution of density in the mantle. These predictions can be tested against data from geological observables such as the history of plate motions, observations of stress history and uplift, and seismic tomography, and should constrain the role of plate bounding forces in the dynamics of mantle convection and plate tectonics.