Upwelling plumes, superswells and true polar wander - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles Geophysical Journal International Year : 2004

Upwelling plumes, superswells and true polar wander

Abstract

The geological evolution of the rotational axis of the Earth is most likely controlled by internal mass redistribution within the mantle. Palaeomagnetic observations suggest that it is episodic in nature, with periods of quasi-standstill alternating with periods of faster wander. Here, we investigate two models for the influence of mantle plumes that vary at different spatial wavelengths on the time variations of the rotational axis (true polar wander; TPW). In the first model, we represent an upwelling plume as a sphere whose radius varies as a function of the flux of material in the conduit and that traverses the mantle at the Stokes velocity. Such a plume produces very little wander of the rotational axis. We then study the effects of two superswells that mimic the ones observed with seismic tomography and conclude that a doming regime within the mantle involves significant polar wander. Some of the features of this TPW that are directly linked to the periodicity of doming are reminiscent of observed phases of slow and fast TPW, with similar peak velocities.
Fichier principal
Vignette du fichier
159-3-1125.pdf (973.63 Ko) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-03600273 , version 1 (07-03-2022)

Licence

Attribution

Identifiers

Cite

Marianne Greff-Lefftz. Upwelling plumes, superswells and true polar wander. Geophysical Journal International, 2004, 159, pp.1125-1137. ⟨10.1111/j.1365-246X.2004.02440.x⟩. ⟨insu-03600273⟩
15 View
11 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More