Photographs illustrating persistent, axisymmetric, low-viscosity conduits on top of topographic peaks on the dense layer in experiments with (top) free-slip and (bottom) no-slip basal mechanical boundary conditions. Once formed, conduits govern the flow of buoyant fluid from the hot boundary and persist until the dense layer is eroded such that the height of the topography becomes small in comparison t o the thermal boundary layer thickness. The conduits are thus regarded as stable, long- lived structures. The heavy, dark vertical lines in the photographs are thermocouples.
Caption taken from:
Jellinek, A.M., and M. Manga, Links between long-lived hotspots, mantle plumes, D" and plate tectonics, Rev. Geophys., 42, No. 3, RG3002, 10.1029/2003RG000144, 14 September 2004
Image courtesy of Mark Jellinek.