Plate motion and mantle plumes in thermal and themochemical convection

板块运动代表了地幔对流的表面表现。在数值上，应用复杂的流变学方法对其进行研究。为了研究板块运动及其对地幔对流的反馈，我们已经发展了不同的模拟方法。这项提议的目的是调查板块反转。这些被认为是夏威夷帝王链弯曲的一种可能机制，并应与另一种机制(作为地幔对流原因的羽流倾斜)进行比较。我们已经在我们的模型中观察到了这两种机制。然而，在自洽的地幔对流模型中，导致板块反转或羽流倾斜的条件尚不清楚。此外，板块方向变化的频率和强度必须与地球上的观测结果进行比较。可以用倾斜的羽毛来解释像夏威夷皇帝链那样的强烈扭结吗？或者这会导致地表运动的快速变化？有没有可能通过在核-地幔边界施加化学致密物质或特定的流变学来锚定羽流，从而只观察到偶尔的倾斜？

Plate motion represents the surface expression of the mantle convection. Numerically it is studied by applying a complex rheological approach. We have already developed different modelling methods in order to study plate motion and its feedback on mantle convection. The aim of this proposal is to investigate plate reversals. These are considered as a possible mechanism for the bend in the Hawaiian emperor chain and shall be compared to the other mechanism (tilt of a plume as a cause of the mantle convection). We have already observed both mechanisms in our models. However, the conditions leading to plate reversals or a plume tilt in self-consistent mantle convection models are not clear. Furthermore, the frequency and strength of changes in the plate direction have to compared to the observations on Earth. Can a strong kink, as observed for the Hawaiian emperor chain, be explained by a tilting plume? Or does this cause a rapidly changing surface motion? Is it possible to anchor a plume, so that only occasional tilts are observed, by applying chemical dense material at the core-mantle boundary or a specific rheology?