Evaluating the contribution of plate boundary forces and mantle flow on the late Cenozoic North American plate motion history with coupled global models of mantle and lithosphere dynamics

板块运动变化对构造板块的驱动力和阻力具有很强的制约作用。在这里，我建议使用能够描述板块边界和地幔对流相关力的全球地幔和岩石圈动力学耦合模型，来利用最近以高时间分辨率绘制的北美相对于努比亚和欧亚大陆的新近纪速度图，分别显示了15 Ma和7 Ma的两次突然减速。我将把这些信息与北美西部新生代隆起史的地质标志结合起来。数据驱动的模拟方法将使我能够检验来自山脊推覆和大尺度地幔流动的强迫是否足以解释美国板块运动的北东变化，或者是否新近纪黄石热点的到来通过压力驱动(即Poiseuille)上地幔流动施加大量的亚石圈应力来解释这种变化。这项拟议的工作建立在早期经验的基础上，该经验表明，次太平洋软流圈是Poiseuille流的重要组成部分，并提供了通过地球动力学模拟定量解释北美板块运动变化的令人兴奋的可能性，从而有助于阐明主要构造板块的力平衡。

Plate motion changes hold powerful constraints on the driving and resisting forces of tectonic plates. Here I propose to use global coupled models of the mantle and lithosphere dynamics, capable of representing plate boundary as well as mantle convection related forces, to exploit the fact that the Neogene velocity of North America relative to Nubia and Eurasia has beenmapped recently at high temporal resolution, revealing two abrupt slowdowns at 15 Ma and 7 Ma, respectively. I will combine this information with geologic indicators on the Cenozoic uplift history of western North America. The data-driven modeling approach will allow me to test whether forcing from ridge push and large scale mantle flow is sufficient to explain theNorth American plate motion change, or whether the Neogene arrival of the Yellowstone hotspot may have contributed to it, by imparting substantial sublithospheric stresses through pressure-driven (i.e., Poiseuille) upper mantle flow. The proposed work builds on earlier experience indicating that the sub-Pacific asthenosphere features a significant component of Poiseuille flow, and offers the exciting possibility to explain the North American plate motion change quantitatively through geodynamic modeling, thus helping to elucidate the force balance of a major tectonic plate.