There is way more CO2 in Martian Polar Cap than previously thought

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A newly found, buried deposit of frozen carbon dioxide -- dry ice -- near the south pole of Mars contains about 30 times more carbon dioxide than previously estimated to be frozen near the pole. This map color-codes thickness estimates of the deposit derived and extrapolated from observations by the Shallow Subsurface Radar (SHARAD) instrument on NASA's Mars Reconnaissance Orbiter. The orbiter does not pass directly over the pole, and the thickness estimates for that area (with smoother transitions from color to color) are extrapolations.

Red corresponds to about 600 meters or yards thick; yellow to about 400; dark blue to less than 100, tapering to zero. The scale bar at lower right is 100 kilometers (62 miles). The background map, in muted colors, represents different geological materials near the south pole.

The estimated total volume of this buried carbon-dioxide deposit is 9,500 to 12,500 cubic kilometers (2,300 to 3,000 cubic miles).

Known variations in the tilt of Mars' rotation axis can significantly reduce or increase the proportion of the planet's carbon dioxide that is sequestered into this newly discovered deposit, climate models indicate. The Martian atmosphere is about 95 percent carbon dioxide, and this deposit currently holds up to about 80 percent as much carbon dioxide as the atmosphere does. Several-fold swings in the total mass of the Martian atmosphere can result from growing and shrinking of dry ice deposits on time scales of 100,000 years or less, the models indicate.

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I wonder if this would make it easier (relatively speaking) for humans to modify the Martian atmosphere in order to increase the atmospheric pressure.

By Charles Sullivan (not verified) on 21 Apr 2011 #permalink

This deposit alone if returned to the atmosphere would nearly double the atmospheric pressure and thus increase temperature. It would still not be enough for liquid water to exist on the surface, though.
Add some Kuiper-belt object rich in methane, and we would get some real warming. I doubt even all the new sources of ice and carbon dioxide are enough to bring the atmospheric pressure up to one bar, so external sources of volatiles (an idea I think originate with Freeman Dyson) are a must, if you are thinking of actual terraforming.

By Birger Johansson (not verified) on 21 Apr 2011 #permalink

RE #2 - "...and thus increase temperature".

I don't think it's that simple. It's unclear to me that releasing the CO2 deposit into the Martian atmosphere would actually warm Mars. I'm not a cliamtologists but as I understand it the warming effect of CO2 depends on pressure. This is why on Earth the stratosphere is cooling while the troposphere is warming, even though both layers have rising CO2 concetrations.