MICHAEL MANGA: Recent Refereed Publications


Jellinek, A.M, A. Lenardic, and M. Manga (2002) The influence of interior mantle temperature on the structure of plumes: Heads for Venus, Tails for the Earth Geophysical Research Letters, vol. 29, paper number 10.1029/2001GL014624.

To form mantle plumes with large heads and narrow trailing conduits requires large (factor >102) viscosity variations within the hot thermal boundary layer at the plume source. However, if a layer of fluid with a temperature-dependent viscosity is heated from below and cooled from above, convection occurs beneath a stagnant lid, and the interior fluid temperature remains close to that of the hot boundary. Consequently, under conditions of thermal equilibrium the viscosity reduction across the hot thermal boundary layer is only around a factor of 3. Subduction of the stagnant layer (equivalent to recycling lithospheric plates on the Earth) will cool the interior of the mantle, thus increasing the viscosity ratio. Hence, the existence of Earth-like mantle plumes may be a consequence of plate tectonics. An absence of plate tectonics on Venus may lead to a flow composed of discrete plumes, the surface expression of which are coronae, as well as a relatively smaller core heat flux.

Return to Michael's home page
Back to list of publications