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.

[glennwsmith]

Whoa! Marsbug and Doc, thanks for alerting me to the fact that the question of an Oceanus Borealis is entangled (as of course it must be) with the heated debates regarding basal surge versus water-based processes. I have been involved in that frustrating loop myself when I, along with Dvandorn and many others, remarked on the incredible layering of Meridiani. So part of my goal with this thread is to approach things from a different, simplistic angle: was there (or is there still, in frozen form) a vast ocean in the northern basin? When Phoenix landed on a sheet of ice, and when meteorites at widely spaced intervals are turning up ice, the presence of such seems likely to me. Interestingly, even Dburt advances the possibility of a northern ocean, in post #36 from the thread which Marsbug turned me on to, "Welcome Professor Brine Splat":

"Large amounts of water apparently survived in the subsurface, however, as both ice and (probably) deep brine (as evidenced by occasional catastrophic releases to outflow channels that possibly formed ephemeral seas in the northern lowlands)."

And I will now succumb to the temptation to use an emoticon: