18th
March
2007
Mars under water!
posted by saurabh in Arts & Crafts, Starry-eyed, The Future |Some of you may have seen the news that a large amount of water ice has been discovered hidden under Mars’ south pole. Supposedly this is enough to cover the entire surface of Mars to a depth of 10m. Pretty cool!
Of course this doesn’t make much sense, since water falls to the lowest point it can, so it’s reasonable to ask what Mars would look like if all this water flowed down to fill basins. I did a pretty naive approximation of this, the results of which are below.
First we start with a topography map of Mars, courtesy NASA:
This is an equirectangular projection, which makes math easy on us. Given the surface area of Mars, we know how much water is sitting around (in cubic meters) based on the above figure. If we assume that this could all sit on top of the dry Martian surface without it being sucked up like a sponge (doubtful), we can work out what height this would fill merely by subtracting away the terrain. This works out to a height of 90m, surprisingly enough. Mars seems to be pretty flat. So we can flood everything below that:
Then some false coloring and completely fictitious clouds for jazz:
Looks neat! I’d live there.
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what kinds of things live there, do you think?
Looks neat! I’d live there.
Let’s go!
Then some false coloring and completely fictitious clouds for jazz:
Mmm, steamy jazz.
It occurred to me that, having made this map, it might now be our job to name these Martian bodies of water. Any ideas?
Actually, is there any way you could remap the rectangular projection to a globe? I’m having trouble seeing it.
This planet might have a polar ice cap, no? Like modern Antarctica it lets the the currents flow all the way around at the top, so it won’t have that jurassic warming effect when antarctica was connected to other continents and prevented the flow and was all warm and steamy.
It would be kind of fun to have at least one watery feature named after Kartikkeya. I was thinking of an oblique allusion, like, the the Peacock sea or something for the big oval one.
Medimaria also has an interesting ring to it.
This is a great map to create — but frankly, the results look kind of odd! All the land would be in the southern hemisphere? Maybe it’s a trick of the projection, but it appears to be an antarctic pangaea, so to speak. The global version would look like a crystal ball on a wizard’s staff; a blue orb nestled into a green hand.
Regarding an Antarctic pangaea (panariea?): not an unheard of situation. One caveat I should have made: most of the mass of ice is under the southern pole, and I didn’t even attempt to account for the removal of that mass in my calculation, which would presumably leave a huge-ass hole (huge asshole?). So, maybe there would be some sea over there, too.
Depending on what kind of atmosphere you give this planet, the temperature balance could be anywhere from Venusian (hot) to current Martian (cold). But if it’s something like Earth’s temperature, there will be a big ice cap at the base of the southern hemisphere. The geologic record seems to show that when there is land over a pole, the climate cools on Earth, apparently because of ice caps and albedo. Sea ice isn’t nearly as permanent as a terrestrial ice cap — note the difference between Greenland and its oceanic neighborhood.
Continental weather is much more intense than oceanic weather. The big mountainous land area on the left side of the map would be expected to have Siberian, Gobi, Himalayan types of extremes of moisture, temperature and seasonality. (Mars rotates at 25 degrees off the plane of its orbit around the sun; Earth is at 23.5 degrees; hence Mars would be somewhat more seasonal than Earth.) Just something to keep in mind as you amend the clouds.
The northern ocean could be expected to have a near-perfect Coriolis effect, creating very powerful Hadley cells — air rising at the equator and tumbling at the midlatitudes into great rainstorms; whirling northward and dissipating before reaching the pole.
Hooray, we can talk about something more fun than the war!
And now the rub:
I suspect that the reason we don’t see water on Mars is that volcanism ceased on that planet. Volcanism smelts metal oxides and releases water in the great plumes one sees daily at Popocatapetl, for example. (CO2, sulfur gases and other fumes also escape, but water is the biggest component of any volcanic eruption.) When volcanism ceased, the surface water mostly got stuck in iron oxides. (I’ve suggested this to planetary scientists in the past and gotten shrugs of agreement along with a great deal of indifference. It’s annoying.) If there is a hidden ice cap under the south pole, it would be a shame to melt any of it, as it won’t remain liquid for long — on Mars, water is a nonrenewable resource that gets chemically bound to metal, just as oil is a nonrenewable resource here. Shit, we’re back to the war.
It just occurred to me that the problem for you, Saurabh, being so damn brilliant is that no one has yet said the obvious — nice work with the map! Very cool. Are you saying you added up the volumes of the layers at each elevation until it equalled the volume of the water in the ice cap? Cool stuff. And in addition to being a fascinating effort in fantasy mapping, that is also one of the best procrastinations I have ever seen.
a fascinating effort in fantasy mapping, that is also one of the best procrastinations I have ever seen
This makes me laugh for entirely big-sister related reasons.
How did you come up with the 90m number, please?
oops typo in email, last post
The reason I ask is that http://www.psrd.hawaii.edu/WebImg/MOLA-flood.jpg shows water to a depth of 1000m floods just the northern lowlands, and to almost 1500m only slightly more.
Hmm. Did I have an error? Looking at the topomap, it seems wrong. I got that height via the topomap above and the total volume in the ice caps.
Yep, checked my math and it seems I made a mistake; forgot to convert some units. The actual height should be ~3500m, which only floods the lake/sea in the south. I’m not sure how the MOLA reconstruction worked; maybe they ignored that lake.
Sigh. This is why peer review is useful. Thanks for the double-check.