This is a project to develop finite element numerical models of hydrothermal circulation at an ocean ridge axis. The modeling will specifically focus on along-axis circulation driven by heat transfer from a magma chamber. Various effects such as anisotropic permeability, combined fracture and porous permeability, variable heat input and double diffusive convection. The model results will be constrained to the extent possible by observational and field data from ocean ridge crests and ophiolites. %%% Hydrothermal heat transfer at the sea floor represents approximately 30% of the earth's heat budget. The details of the hydrothermal circulation are not well known. This project will evaluate a number of potential factors that control the pattern and duration of the circulation. Dr Haymon has a great deal of observational and field expertise, which will be very useful for putting the numerical models into a geologic context. Dr. Spera is a very able numerical modeler.