Geoid and topographic swells over temperature-dependent thermal plumes in spherical-axisymmetric geometry
Article first published online: 7 DEC 2012
Copyright 1997 by the American Geophysical Union.
Geophysical Research Letters
Volume 24, Issue 23, pages 3093–3096, 1 December 1997
How to Cite
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Accepted: 6 OCT 1997
- Manuscript Received: 15 JUL 1997
Geoid and topographic profiles over constant-viscosity thermal plumes in spherical-axisymmetric geometry at moderate Rayleigh numbers are compared with results from previous studies in other geometries. Plumes in spherical-axisymmetric models produce larger geoid anomalies than plumes in either Cartesian or cylindrical-axisymmetric geometries; however, the topographic anomalies over the plumes are smaller than the corresponding anomalies in a cylindrical-axisymmetric geometry but larger than those in a Cartesian geometry. For plumes in a temperature-dependent viscosity fluid, the geoid and topographic profiles are reduced by a factor of two when compared to a constant viscosity fluid with the same background viscosity profile. In this case, the radially-averaged temperature profile around the plume creates a low-viscosity ‘layer’ beneath the lithosphere.