Modelling and prediction of dynamical impact of mantle convection on global surface processes

在地壳下的岩石地幔中的热力发动机的特点是在我们星球内部数千公里的垂直和水平距离上进行大规模的质量和热量运输。这种热岩的连续流动，被称为热对流，施加驱动地表构造板块水平“漂移”的力，在地壳中产生变形，这些变形被大的，通常是破坏性的地震放松。这些地球深部的力量还使大陆和洋底产生数百米的垂直位移，从而造成相对海平面的变化，在过去的地质时期，这种变化淹没了大陆内部的大部分地区。这些垂直运动还可以改变地球的外部形状，以至于它们扰乱了地球相对于太阳的轨道倾角，从而影响到我们星球上气候周期的演变。在这个建议中，我们提供了一个雄心勃勃的和令人兴奋的一系列新的举措，直接建模和预测地幔对流对这些广泛的表面过程，形成了地球表面环境的演变在地质时间跨度的动态影响。通过我们正在开发的数值对流代码的改进，以重建地质历史中地球内部的演变，我们将模拟影响两个大陆的基本动力过程，特别是北美和非洲，这些包括：（1）动态表面地形和侵蚀;（2）海岸边缘的稳定性和海平面变化;（3）表面应力模式和地震活动。利用这些对流模型，我们还将对过去6000万年来地球外部形状和旋转变化的全球尺度变化进行详细预测，从而为地幔对流如何影响地球的古气候周期提供新的见解。我们还将通过对全球地震和对流数据进行一系列新的联合反演，力求大大提高我们对三维地幔结构的认识。这些对地球系统运作的创新研究将通过HQP的参与和培训以及我们将促进的多种国际合作来推进。

The heat engine inside the rocky mantle below Earth's crust is characterised by the very large scale transport of mass and heat across vertical and horizontal distances of thousands of kilometres inside our planet. This continuous flow of hot rock, termed thermal convection, exerts forces which drive the horizontal 'drift' of the surface tectonic plates, generating deformations in the crust which are relaxed by large, often destructive earthquakes. These deep Earth forces also produce vertical displacements of the continents and ocean floor across distances of hundreds of metres, thereby producing relative sea level variations which have indundated large portions of continental interiors in the geologic past. These vertical movements can also change the external shape of the Earth to such an extent that they perturb its orbital inclination relative to the Sun and can thus affect the evolution of climate cycles on our planet. In this proposal we provide an ambitious and exciting series of new initiatives to directly model and predict the dynamical impact of mantle convection on these wide ranging surface processes which have shaped the evolution of Earth's surface environment over geological time spans. Through refinements of numerical convection codes which we are developing to reconstruct the evolution of Earth's interior in the geologic past, we will model fundamental dynamical processes affecting two continents in particular, North America and Africa, and these include: (1) dynamic surface topography and erosion; (2) (in)stability of coastal margins and sea level variations; (3) surface stress patterns and earthquake activity. Using these convection models we will also make detailed predictions of the global-scale changes of Earth's external shape and rotation variations over the past 60 million years, thus providing new insights on how mantle convection may affect Earth's palaeoclimate cycles. We will also seek to substantially improve our knowledge of the 3-D mantle structure by carrying out a new series of joint inversions of global seismic and convection data. These innovative investigations into the workings of the Earth System will be advanced by the participation and training of HQP and through multiple international collaborations which we will foster.