Earthlike Mars? Options

[glennwsmith]

All, I know this isn't the right place for this post, but I've looked around and can't find an appropriate, current UMSF forum (Doug, perhaps you could give me some guidance on establishing such) -- so here goes: I think a [the] new paradigm for Martian geology is rapidly coalescing, namely, that Mars is very much like the Earth in terms of the preponderance of water -- except that it is all frozen, and covered under a thin layer of dust/regolith! See, for example, this article:

http://www.skyandtelescope.com/news/41995902.html

Hence the "seepages" found in crater walls; hence the evidence of catastophic flooding -- the result of volcanism melting huge pockets of ice. And I am going to add my own wrinkle (probably not original): that the differentiation of Mars into a rougher southern hemisphere and smoother northern hemsphere represents something like Earth's Pangea stage, ie, the northern hemisphere is a vast frozen sea covered with a thin layer of ice.

[ngunn]

Tim Parker I'm really delighted you're here. I always believed in those shorelines, even when it turned out they aren't level now and even though their morphology is quite unlike terrestrial shorelines.

[stevesliva]

Tim Parker I'm really delighted you're here. I always believed in those shorelines, even when it turned out they aren't level now and even though their morphology is quite unlike terrestrial shorelines.

When the ice sheets on Earth retreat, the underlying crust springs up somewhat. If an entire ocean-size sheet on Mars sublimated, the crustal relaxation wouldn't necessarily be even. Nor would it necessarily be analogous to Earth, because a mantle might be necessary. I just mean to throw out the point that the elevations around that amount of mass might change once it disappears.
http://en.wikipedia.org/wiki/Post-glacial_rebound

Of course it's also interesting to think along the lines of the hemispherical elevation / cratering dichotomy as indicating that there wasn't a total rebound.