GEOPHYSICS: Core-Mantle Boundary Cells

Geophysics. A new paradigm for Earth's core-mantle boundary.

Geophysics. Are Earth's core and mantle on speaking terms?

Avalanches at the core-mantle boundary

The partial collapse of topographic structure at the core-mantle boundary (CMB) in avalanches, slumps or turbidity flows, would cause sudden temperature changes in both the upper core and the lower mantle. Although such collapses are hypothetical, it is interesting to investigate the potential consequences. Downwelling from such events could disrupt core convection cells and trigger geomagnetic...

Geomagnetic spikes on the core-mantle boundary

Extreme variations of Earth's magnetic field occurred in the Levant region around 1000 BC, when the field intensity rapidly rose and fell by a factor of 2. No coherent link currently exists between this intensity spike and the global field produced by the core geodynamo. Here we show that the Levantine spike must span >60° longitude at Earth's surface if it originates from the core-mantle bound...

Incompressibility at the earth's mantle-core boundary.

(1) Introduction.-In this paper, the values of variables at the base of the mantle and top of the core in the Earth models to be considered will be indicated by the subscripts 1 and 2, respectively; k and p will denote the incompressibility and density; let Ak = k2ki and Ap = p2 pi. In an earlier Earth model,1 Model A, k1 = 6.5 X 1012 dyn/cm2 and k2 = 6.2 X 1012 dyn/cm2, giving Ak = -0.3 X 1012...