Core-mantle relative motion and coupling

Nonlinear Core-mantle Coupling

We explore the nonlinear dynamics of a forced core-mantle system. We show that the free axisymmetric motion of a uniform-vorticity Ñuid core coupled to a rigid mantle (the model) is Poincare -Hough integrable. We derive an approximate Hamiltonian for the core tilt mode that includes the leading nonlinear contribution. We then include gravitational perturbations in the analysis. We identify the...

Topographic Core-Mantle coupling in Geodynamo modeling

A 3-dimensional, fully nonlinear numerical geodynamo model is used to study the core-mantle coupling arising from a non-hydrostatic pressure field acting on an aspherical core-mantle boundary (CMB) based on a seismological model. The simulation results demonstrate that the topographic coupling torque is close to being proportional to the square of the amplitude of the CMB topography. We conclud...

Silicon Mantle/core Fractionation and the Origin

Experimentally determined metal/olivine partition coefficients and diffusion rates will help answer questions relating to Earth's elevated Mg/Si ratio and will provide better tools for the determination of the origin of pallasites. It is known that the Mg/Si ratio of the Earth's primitive upper mantle (PUM) is elevated relative to all types of chondrites (possibly not CV chondrites), Mars, and ...

Mantle and Core of the Earth

Core-Mantle Boundary Structures and Processes

The past two decades have witnessed tremendous progress in seismological, geodynamical, geomagnetic, and mineral physics efforts to quantify deep Earth processes. Our understanding of structures and processes in the lowermost mantle has advanced accordingly, and there is now widespread agreement that some form of major thermo-chemical boundary layer (TCBL) exists on the mantle side of the core-...