THEORETICAL MODELING OF ERUPTION PLUMES ON VENUS

A theoretical model of eruption plume dynamics (Woods, 1988) is used t o investigate Plinian eruption columns on Venus. Results for a typical plume, in terms of the temperature, density, velocity, and radius as a function of height are given. The effects of the atmospheric pressur e, the volatile content and species, and the eruption temperature on t he development of high convecting plumes are discussed, demonstrating the combinations of initial conditions giving rise to either high conv ective plumes, or low fountains feeding pyroclastic flows. The results show that the development of high convecting plumes on Venus requires an unlikely combination of high volatile contents, high initial tempe ratures, and high altitude eruptions, leading to the conclusion that e xplosive eruptions on Venus will generally lead to pyroclastic flows.