AN INVESTIGATION OF EPISODIC LIQUID WATER RELEASE AT MARS SURFACE CONDITIONS

For many years, the presence of flow features at the surface of Mars has presented researchers with a bit of a paradox. While the evolution of fluvial erosional and depositional landforms is well-studied and understood, the actual presence of liquid required to create such forms is difficult to reconcile with the normal temperature and pressure conditions at the surface of the planet. At approximately 0.7kPa, the relatively low surface pressure would appear to prevent water from entering a liquid phase, instead sublimating directly from solid ice to vapor. However, the presence of liquid water is widely regarded as a necessary cause of the features mentioned above. Recent observations by the Mars Orbiter Camera have indicated that these channels and outwash gullies continue to be formed even today, and if these features are truly fluvial in origin, they necessitate an extant source of water as well as episodic if not periodic releases in liquid form.

Researchers have previously suggested that under some conditions, frozen subsurface ice deposits may occasionally release varying amounts of water to the surface that exists for a short time in liquid form. For this study, I used known ranges of Mars' surface temperature and pressure as well as regolith density to examine the possibility of liquefaction of subsurface bodies of ice due to overburden weight and seasonal temperature fluctuations. Additionally, I investigated the effects of varying size and density of particulate matter on the pressure liquefaction of the ice matrix.

Currently, the size and composition of any subsurface water deposits is not known, but studies of laboratory analogues such as these can provide us with important insight into processes which likely continue to operate to reshape the surface of Mars.