Mars’ polar ice canyons are young and the source for mid-latitude ice
Mars’ north polar ice cap.
Scientists have now proposed that the giant ice canyons seen at the edges of Mars’ polar ice caps are very young and are also the source of the water that sublimates away when the planet’s rotational tilt (its obliquity) is high, to fall as snow in the mid-latitudes where it forms the glaciers and ice sheets we now find there.
The image to the right, reduced to post here, shows the entire north pole ice cape on the left, with its spiral canyons. The two inserts on the bottom show for scale Hawaii’s Big Island and the Grand Canyon. From the release:
“Erosion formed a huge ice canyon system, and that erosion is a source of the long-known mid-latitude mantles on Mars,” said Rodriguez, lead author of “North polar trough formation due to in‑situ erosion as a source of young ice in mid‑latitudinal mantles on Mars” that appears in Nature Scientific Reports.
The troughs are arranged in a vast spiral pattern covering an area the size of Texas. We find that their growth lateral to katabatic wind (wind that carries high-density colder air from a higher elevation down a slope) directions produced widespread simple intersections, from which the highly complex spiral arrangement emerged, Rodriguez said. “The spiral pattern seen in the troughs is basically an erosional byproduct,” he said. “As the pits grow and intersect over a pre-existing dome-shaped polar cap, the spiral pattern emerges.
“It has long been proposed that sublimation of water ice from the north polar cap during high-obliquity cycles was an essential source of the planet’s mid-latitude icy plains. Our finding identifies the troughs as direct evidence of those sublimation phases,” Rodriguez said.
These spiral trough features formed very recently, in geologic terms: between a few million and 50,000 years ago, Rodriguez said.
This hypothesis, if true, is very important in understanding the long term geological history of Mars. The present theory is that when the obliquity rises to as high of 60 degrees, compared to today’s 25 degrees (similar to Earth’s), the mid-latitudes are colder than the poles, and the ice at the poles then migrates to the mid-latitudes. This paper gives us the place at the poles where the icecap shrinks as that ice sublimates away.
Knowing that these polar canyons are young and the source of the mid-latitude ice scientists can now begin to write the geological history of the polar ice caps themselves. They can also use this information to maybe determine whether the caps are presently in a steady state, as now believed, or growing or shrinking.
The youth of these canyons also suggests that any mid-latitude ice from them is also young, and thus more likely pure water unpoisoned by the toxic perchlorates found in many places on the Martian surface. It will thus be easier to obtain pure drinkable water from them.
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Mars’ north polar ice cap.
Scientists have now proposed that the giant ice canyons seen at the edges of Mars’ polar ice caps are very young and are also the source of the water that sublimates away when the planet’s rotational tilt (its obliquity) is high, to fall as snow in the mid-latitudes where it forms the glaciers and ice sheets we now find there.
The image to the right, reduced to post here, shows the entire north pole ice cape on the left, with its spiral canyons. The two inserts on the bottom show for scale Hawaii’s Big Island and the Grand Canyon. From the release:
“Erosion formed a huge ice canyon system, and that erosion is a source of the long-known mid-latitude mantles on Mars,” said Rodriguez, lead author of “North polar trough formation due to in‑situ erosion as a source of young ice in mid‑latitudinal mantles on Mars” that appears in Nature Scientific Reports.
The troughs are arranged in a vast spiral pattern covering an area the size of Texas. We find that their growth lateral to katabatic wind (wind that carries high-density colder air from a higher elevation down a slope) directions produced widespread simple intersections, from which the highly complex spiral arrangement emerged, Rodriguez said. “The spiral pattern seen in the troughs is basically an erosional byproduct,” he said. “As the pits grow and intersect over a pre-existing dome-shaped polar cap, the spiral pattern emerges.
“It has long been proposed that sublimation of water ice from the north polar cap during high-obliquity cycles was an essential source of the planet’s mid-latitude icy plains. Our finding identifies the troughs as direct evidence of those sublimation phases,” Rodriguez said.
These spiral trough features formed very recently, in geologic terms: between a few million and 50,000 years ago, Rodriguez said.
This hypothesis, if true, is very important in understanding the long term geological history of Mars. The present theory is that when the obliquity rises to as high of 60 degrees, compared to today’s 25 degrees (similar to Earth’s), the mid-latitudes are colder than the poles, and the ice at the poles then migrates to the mid-latitudes. This paper gives us the place at the poles where the icecap shrinks as that ice sublimates away.
Knowing that these polar canyons are young and the source of the mid-latitude ice scientists can now begin to write the geological history of the polar ice caps themselves. They can also use this information to maybe determine whether the caps are presently in a steady state, as now believed, or growing or shrinking.
The youth of these canyons also suggests that any mid-latitude ice from them is also young, and thus more likely pure water unpoisoned by the toxic perchlorates found in many places on the Martian surface. It will thus be easier to obtain pure drinkable water from them.
Readers!
Every February I run a fund-raising drive during my birthday month. This year I celebrate my 72nd birthday, and hope and plan to continue writing and posting on Behind the Black for as long as I am able.
I hope my readers will support this effort. As I did in my November fund-raising drive, I am offering autographed copies of my books for large donations. Donate $250 and you can have a choice of the hardback of either Genesis: the Story of Apollo 8 or Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space. Donate $200 and you can get an autographed paperback copy of either. IMPORTANT! If you donate enough to get a book, please email me separately to tell me which book you want and the address to mail it to.
Please consider supporting my work here at Behind the Black. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Every one of those 2020 conclusions has turned out right.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
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