The Plume-Thermal Dichotomy of Venus: A Numerical Approach
Madeleine Kerr, University of California, San Diego
How do we know if Earth is uniquely able to support life, or if features of our planet are a common occurrence in our galaxy and universe? We do not have a lot of comparison points, but our closest proxy for Earth-sized terrestrial planets is Venus. Venus and Earth differ in numerous ways, including the surface structure or topography of the planet. On Earth we have plate tectonics moving around a convecting mantle and on Venus there is only one encompassing hard "plate" called the lithosphere. On Earth we have volcanism on plate boundaries and from buoyant upwellings deep in the planet called mantle plumes. On Venus, however, there are these same mantle plumes and also smaller upwelling sites called coronae (a "crown" shaped circular fractured zone much smaller than mantle plumes) which do not appear on Earth. The strange coexistence of these features in regions of Venus such as the Alta-Beta-Themis (or BAT) region is called the "plume-thermal dichotomy" and the mystery is how to form multiple scales of volcanism in one region. This research will present a methodology of exploring how the dichotomy could have happened using 2-D numerical finite volume models and a novel analysis method of convective regimes and plume sizes using unsupervised learning. Preliminary data from Boussinseq (incompressible) models with strong temperature viscosity illustrates the usefulness of the analysis method which will then be applied to more complex planetary interiors, such as those with heterogeneous initial temperature fields, extended-boussinesq flow, and chemically dense layers as well. With this information we can constrain the conditions of Venus's formation and isolate the features that differed so greatly in Earth and Venus's respective evolutions.
Authors: M.C. Kerr1, D. A. Stegman1, A. Adams1, S. Smrekar2
1Scripps Institution of Oceanography, California, USA
2Jet Propulsion Laboratory, California, USA
Abstract Author(s): (see above entries)