>>12674493Like nothing on Earth, which is to be expected.
Soil minerals are for the most part different, atmosphere will be totally different, water cycle will be different, weather patterns will be different (no massive oceans to supply humidity and heat to stabilize rainfall patterns), etc etc.
As Mars' atmosphere is thickened and temperatures rise, the lowland areas will begin to see surface water flows for the first time in billions of years. However since Mars has such a massive terrain scale height what we will probably see is the migration of water ice from permafrost underground to the surface as high elevation frost deposits, as humid air from the lowlands is blown over the highlands and freezes out. Eventually as more air builds up these frost glaciers would also begin melting rather than sublimating, which will allow the formation of glacial streams that will flow down and likely join into decently sized rivers of water, carrying salts and soluble minerals down form the highlands. These mountain rivers will almost certainly not terminate in lakes, but instead will fan out across wide areas of the northern plains until they evaporate or soak into the ground. The result will be the formation of large fans of sediments deposited by these rivers, fringed by huge salt deposits. If we are also adding water to Mars/digging it up out of the mantle, increasing the hydrosphere mass, eventually the amount of water circulating will exceed the level necessary to form large ocean-like reservoirs of water, which will slowly become more salinated as the water cycle continues.
To a degree the scale height will always be an issue on Mars; if we assume 1 bar of pressure at the Martian "zero" elevation level, then most of the southern hemisphere and especially the Tharsis region will be effectively uninhabitable to unprotected humans. This will have permanent and unavoidable effects on climate, though not necessarily unmanageable ones.
