(ORDO NEWS) — Carbon dioxide glaciers are moving today, creating kilometers-thick deposits in the south polar region of Mars that could last for more than 600,000 years, Isaac Smith, a research fellow at the Planetary Science Institute, said in a paper.
“It turns out that CO2 deposits that were first discovered in 2011 are flowing today, as are glaciers on Earth,” said Smith, lead author of “Carbon Dioxide Glaciers at the South Pole of Mars,” published in the Journal for Geophysical Research. -Planets.
“About 600,000 years ago, CO2 ice began to form at the Martian south pole. Due to climatic cycles, the ice increased in volume and mass several times, punctuated by periods of mass loss due to sublimation,” Smith said.
“If ice never drained, it would mostly be where it was originally deposited, with the thickest ice only about 45 meters thick. Instead, as it flowed downslope into pools and spiral troughs curvilinear pools “Where it settled, it was able to form deposits up to one kilometer thick.”
“Glaciers have enough mass to sublimate to double the atmospheric pressure on the planet. This is a staggering amount, and the 2018 paper by PSI Senior Scientist Tan Putzig measured it most accurately,” Smith said. “The longest glacier is about 200 kilometers long and about 40 kilometers across.
These are large glaciers! This activity continues, but the flow rate probably peaked around 400,000 years ago, when deposition was at its greatest. We are now in a slow period, because the mass of ice is decreasing, and this slows down the movement of glaciers.
Recent work, done in part at PSI (and funded by Smith), has investigated the laws of flow, or strength properties, of carbon dioxide ice.
This work showed that CO2 ice flows nearly 100 times faster than H2O ice in Martian conditions and on high slopes. This is why CO2 ice behaves like glaciers while the rest of the H2O ice cap that supports it appears to be stationary.
Analysis of glacier modeling results with the NASA ice sheet system and sea level model, supported by two co-authors and adapted by Smith to work on Mars and with CO2, showed that CO2 ice was not moved by typical methods.
“Atmospheric precipitation would place the ice in a form that we can’t see. It would be much more evenly distributed and thinner. What the interpretation of the glacier gives is a mechanism for moving ice from high places to lower basins, which are also in lower latitudes,” Smith said.
“If atmospheric precipitation were the only process affecting ice, then most of it would be at the highest latitudes and at the highest altitudes. But this is not the case. Ice flows down the slope into pools, much like water flows down the slope into the lake.
Additional work by Smith and his team has revealed several surface features that are very good analogs of the features we see on terrestrial glaciers. These include topographic profiles, crevices, and compression ridges that resemble earth features. This strengthened the findings and provided a basis for comparison with models.
Earth, Mars and Pluto are the only bodies in the solar system known to have actively flowing ice, but they are probably not alone.
There are many types of ice in the solar system, and as the number of dwarf planets grows, it is likely that some of them have carbon monoxide or methane glaciers even more exotic than the dry ice glaciers just discovered on Mars.
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