Modeling of fluidized ejecta emplacement over digital topography on Venus

Journal of Geophysical Research E: Planets
By:  and 

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Abstract

The FLOW computer model of McEwen and Malin (1989) modified for application to the study of Venus fluidized ejecta blankets (FEBs) demonstrates that relatively low viscosities, yield strengths, and initial velocities are required to duplicate the observed flow paths of the outflow materials. The model calculates the velocities and simulated flow paths of gravity flows over Magellan topography. The model is formulated to determine flow movements from initial conditions, gravitational acceleration, and resistance to motion as described by Coulomb, viscous, and turbulent resistance forces. Successful duplication of observed FEB flow paths has been achieved for the FEB craters Addams, Isabella, and Cochran. When used as a simple energy‐line model, the model requires low coefficients of friction to extend FEBs to near their observed termini in the synthetic aperture radar (SAR) imagery, although the resulting straight flow lines do not follow the observed flow paths well. For Bingham flow, the model requires low values of viscosity and yield strength which are more similar to pyroclastic or debris flows than basaltic lavas. Flows of 100‐m depth require 1 to 2 orders of magnitude higher values of both viscosity and yield strength than 10‐m‐deep flows. The complicated nature of the flow lines for the low velocity model suggests that FEBs were probably emplaced under variably laminar and turbulent flow conditions, where underlying topography influenced both the direction and energy of flow materials.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Modeling of fluidized ejecta emplacement over digital topography on Venus
Series title Journal of Geophysical Research E: Planets
DOI 10.1029/95JE02361
Volume 101
Issue E2
Year Published 1996
Language English
Publisher American Geophysical Union
Publisher location Washington, D.C.
Contributing office(s) Astrogeology Science Center
Description 10 p.
Other Geospatial Venus