Pre-global surveyor evidence for Martian ground water

A time-dependent theory for the evolution of water on Mars is presented. Us ing this theory and invoking a large number of observational constraints, I argue that these constraints require that a large reservoir of water exist s in the Martian crust at depths shallow enough to interact strongly with t he atmosphere. The constraints include the abundance of atmospheric water v apor, escape fluxes of hydrogen and deuterium, D/H ratios in the atmosphere and in hydrous minerals found in one Martian meteorite, alteration of mine rals in other meteorites, and fluvial features on the Martian surface, Thes e results are consonant with visual evidence for recent groundwater seepage obtained by the Mars Global Surveyor satellite.