@rosborne979,
Many planetologists believe that the surface sands and dusts of Mars are heavy with salts, and so far, the scant data we have bears them out. Brine might not necessarily be ubiquitous, but if those ladies and gentlemen are correct, than any liquid water on the surface would rapidly become salty. The highest daytime temperatures on Mars will be in the southern hemisphere in summer, and as it is now southern hemisphere spring, Curiosity may have found briny water because it is now just melting out of the upper levels of the regolith. Day time high temperatures south of the Martian equator in Martian summer can reach almost 70 degrees Fahrenheit. I'm not exactly certain what daytime highs are right now, but above freezing may well be the case.
Schiaparelli's telescope (and most people's telescopes then and for decades to come) did not have the resolution to give them enough detail to distinguish liquid hyrological flow from glacial flow. He did the best with what he had available. I don't have enough information to comment on whether the channels he identified were from liquid water or glaciers. Operating in good faith, Schiaparelli had thought the four huge albedo features on and near the Tharsis plateau were lakes--and so he named them: Olympus Lacus, Arsia Lacus, Phoenicis Lacus and Ascraeus Lacus. By the mid-20th century, some obervatories had begun to suspect that those albedo features were perhaps higher elevations, because their time-lapse photography seemed to show moving shadows. Some were confident enough to rename Schiaparelli's lakes, calling them Olympus Mons, Arsia Mons, Pavonis Mons (i don't know why they changed the name from phoenix to peacock) and Ascraeus Mons. Mariner 4, which flew by Mars in 1965, confirmed that they are mountains, extinct volcanoes, in fact. They are the largest mountains and volcanoes in the solar system, by orders of magnitude--Olympus Mons is more than a hundred times as massive as Mauna Loa, the largest volcano on our planet.
Schiararelli's telescope lacked the resolution to tell him that the flow channels he saw were in canyons. I don't believe that right now anyone would tell with any certainty if the flow created the canyons or if the canyons channeled the flows. Schiaparelli (and most other astronomers) were completely unaware of the massive canyon system which stretches east from the southeast edge of the Tharsis plateau and which has been named, within the last 50 years, the Valles Marineris, in honor of the humble little robots which first photographed Mars from close range. Schaparelli named one pattern of flows Noctis Labyrinthus (the Labyrinth of Night) rather fancifully, certainly, but because of the way the channels wove together. I don't believe he had any idea that it was a deep, narrow canyon running hundreds of kilometers.
The Valles Marineris are even more impressive. If the western end were laid on Portland, Oregon, the southeastern end would reach Miami. In the Melas Chasma, if you were standing in the middle, you would not see the cliffs either to north or south, even though they are more than 10,000 feet high. Liquid or glacial, it was a gargantuan flood which once carved the channels in this canyon system. Even this incredibly vast canyon system was not discovered until 1971 or -72.
For all that we've been exploring this neighbor of ours for half a century, we know so very little about it. We may never go there (meaning those of us chewing the fat here), but there will be many new things to learn and many surprises even in the short times we still have on this Earth.
