Introduction: The amount of water in and distribution of water between the various martian water reservoirs (atmospheric, hydrospheric, interior) are outstanding questions in martian science. Kaersutitic (Ti-rich) amphibole and apatite, the few water-bearing minerals present in the martian meteorites, have been studied to gain insight into all three martian water reservoirs. The igneous nature of the kaersutites and apa-tites connects the phases to the interior, or magmatic, water reservoir. Their residence time in the crust provides opportunity for the phases to interact with the atmospheric and hydrospheric reservoirs. The combined influence of the reservoirs is imprinted in the low water contents and high, variable H isotopic compositions of the kaersutites and apatites. Variations of up to δD = 900‰ exist within individual and between different grains [1]. Water content and H isotope measurements of one of the Martain apatites were made in an attempt to separate the signatures of the magmatic and atmospheric/hydrospheric (assumed to be in communication) reservoirs [2]. Results of the study led to a constraint on the H isotopic composition of the magmatic water reservoir and to the important conclusion that the hydrospheric reservoir is 2-3 times larger than previously determined [2]. Such a study illustrates the power and importance of understanding the water contents and H isotopic signatures of martian water-bearing minerals. The water content and H isotopic composition of geologic materials, however, can be influenced via shock experienced in the impact process, the process which liberated the martian meteorites. Impact-induced loss of water and enrichment of H isotopic composition at shock pressures comparable to those experienced by the kaersutite-bearing martian meteorites (20-35 GPa) was demonstrated by [3]. If water contents and H isotopic compositions of martian water-bearing minerals were influenced by shock, such an effect could influence conclusions about the amounts of water present in and interactions between martian water reservoirs. In order to investigate the ability of shock to influence water, and in turn the validity of arguments based on martian kaersutite water contents and H isotopic compositions, we have conducted a series of shock experiments on terrestrial amphibole samples. Experimental: Three samples of kaersutitic megacryst amphiboles with initial water contents of