Abstract While mantle convection is a fundamental ingredient of geodynamics, the driving mechanism of plate tectonics remains elusive. Are plates driven only from the thermal cooling of the mantle or are there further astronomical forces acting on them? GPS measurements are now accurate enough that, on long baselines, both secular plate motions and periodic tidal displacements are visible. The now >20 year-long space geodesy record of plate motions allows a more accurate analysis of the contribution of the horizontal component of the body tide in shifting the lithosphere. We review the data and show that lithospheric plates retain a non-zero horizontal component of the solid Earth tidal waves and their speed correlates with tidal harmonics. High-frequency semidiurnal Earth's tides are likely contributing to plate motions, but their residuals are still within the error of the present accuracy of GNSS data. The low-frequency body tides rather show horizontal residuals equal to the relative motion among plates, proving the astronomical input on plate dynamics. Plates move faster with nutation cyclicities of 8.8 and 18.6 years that correlate to lunar apsides migration and nodal precession. The high-frequency body tides are mostly buffered by the high viscosity of the lithosphere and the underlying mantle, whereas low-frequency horizontal tidal oscillations are compatible with the relaxation time of the low-velocity zone and can westerly drag the lithosphere over the asthenospheric mantle. Variable angular velocities among plates are controlled by the viscosity anisotropies in the decoupling layer within the low-velocity zone. Tidal oscillations also correlate with the seismic release.

中文翻译：

---

板块运动的潮汐调制

摘要 虽然地幔对流是地球动力学的一个基本组成部分，但板块构造的驱动机制仍然难以捉摸。板块是仅由地幔的热冷却驱动的，还是有进一步的天文力作用于它们？GPS 测量现在足够准确，在长基线上，长期板块运动和周期性潮汐位移都是可见的。现在超过 20 年的板块运动空间大地测量记录可以更准确地分析体潮的水平分量对岩石圈移动的贡献。我们回顾了数据并表明岩石圈板块保留了固体地球潮汐波的非零水平分量，并且它们的速度与潮汐谐波相关。高频半日地球潮汐可能导致板块运动，但它们的残差仍然在目前 GNSS 数据精度的误差范围内。低频体潮更显示出等于板块间相对运动的水平残差，证明了板块动力学的天文输入。板块移动速度更快，章动周期为 8.8 年和 18.6 年，这与月球背面迁移和节点岁差有关。高频体潮多被岩石圈和下伏地幔的高黏度缓冲，而低频水平潮汐振荡与低速带弛豫时间相适应，可将岩石圈向西拖至软流圈地幔上方。 . 板之间的可变角速度由低速区内解耦层中的粘度各向异性控制。