Simulating lava flows by an improved cellular automata method

Lava-flow morphology is determined by cooling rate, viscosity, yield strength, eruption rate, topography, total mass, and other various factors. We have made a numerical flow model, assuming nonisothermal laminar Bingham flow, in which we take the self-gravity and cooling mechanisms into account. Because the calculation method is a type of cellular automata on square meshes, we can apply our numerical model on any actual topography based on a dense-grid digital elevation model. A method of eliminating the mesh shape dependence which is a well-known problem of cellular automata, is also presented. This reduced random space method enables us to calculate large-scale lava flows in a short time without numerical instability, and obtain mesh-free reliable results. This method is applicable to any other cellular automata type algorithm with ease. We validate our simulation code using data from a real lava flow. (C) 1997 Elsevier Science Ltd.