The Wall of Westeros Would Be Its Own Worst Enemy

By Nola Taylor Redd | January 12, 2018 12:09 pm

The Wall. (Credit: HBO)

The Wall that defends the Game of Thrones universe would need to be made of more than pure ice if it had stood for over 8,000 years.

According to the plot of George R. R. Martin’s famous book and television series, the massive wall of ice protects humanity from the blue-eyed White Walkers, an ancient race of ice zombies that threaten all living things. But if the wall that shields the realm was made of pure water ice, it would not remain a wall for long; instead, it would quickly become a low hill.

Although it’s easy to think of ice as rock-hard, it’s anything but, especially for a wall reported to be over 700 feet tall. With that in mind, let’s dig into the science of big hunks of ice.

“Ice flows,” says glaciologist and University of Alaska Fairbanks professor Martin Truffer. “The higher the stresses are, the easier it flows, so if you have a wall that high, at the bottom of that, the stresses are so high it would just ooze out like soft butter.”

Truffer looked at how well the infamous wall would stand up under pressure and found that it wouldn’t last long. He presented his results last month at the annual American Geophysical Union conference in New Orleans, Louisiana.

According to Martin’s series, the giant wall runs 300 miles across the northern face of Westeros. The over 8,000-year-old barrier was allegedly built by Bran the Builder to keep the White Walkers out. The Sworn Brothers of the Night’s Watch patrol the Wall, protecting it from the human settlements on the northern side, and watching for the return of the walkers, whose existence have become the stuff of myths and legends. While the Night’s Watch are valiant fighters, the Wall is the primary defense for the realm.

But not a very sure one. According to Truffer, a wall of solid-ice would flow out faster than it could be built, almost immediately oozing into the parabolic shape favored by glaciers. The wall is said to tower over 700 feet high, but Truffer said normal ice would flow down to about half that height.

How quickly the ice spreads depends on the temperature—the colder it is, the longer it takes, Truffer said. But it’s hard to consider that humans could survive the frigid temperatures that might keep the Wall permanently solid. Even if the annual mean temperature averaged -40 degrees Celsius (-104 degrees Fahrenheit), the Wall would flow down to half its height in only a few hundred years. Such low temperatures don’t fit with the Game of Thrones landscape, where the forest butts up against the Wall itself.

“There wouldn’t be any forests growing near there,” Truffer said.

While it’s possible that temperatures dip that low during when winter has come, the warmer summers (which are admittedly still cold up by the Wall) would still cause the Wall to flow to its doom.

“It would still be a barrier, but one you could walk up,” Truffer said.

But all is not completely lost for Westeros. Mixing the ice with rock and dust could help slow the spreading. Truffer didn’t examine how that might play out, but he said rock could be good or bad for the Wall. On the one hand, dusty ice deforms easier than its pure counterpart, which would speed up how quickly the Wall became a hill. On the other hand, if ice contains more than a certain concentration of rock, then it doesn’t deform as easily.

“It’s not straightforward,” Truffer said.

Perhaps the Wall isn’t pure ice. Truffer said that a wall of rock covered with ice “would work a whole lot better.”

“If you wanted to make a wall like that, you would want some sort of structure supporting it,” he said. The rock would then bear up much of the ice’s weight, keeping it from deforming as easily.

In Game of Thrones, tunnels allow the men who guard the Wall to pass from the civilized south to the wild lands of the north. These tunnels create problems of their own, Truffer said. Flowing ice would quickly seal them up.

“I think you could actually watch it close,” he said. “It would just close as you walk through.”

If physics won’t allow the Wall to stand strong, then something else must play a hand.

“There’s got to be magic involved,” Truffer said.

Indeed, magic is hinted at in the fourth book of the series, A Storm of Swords. Spells woven into the wall at its construction help it to stand, and keep the dead from passing through. Perhaps those spells will be enough to save the realm from the White Walkers descending on the wall. Because, as Qhorin Halfhand warned Jon Snow in the novels, “If the Wall should ever fall, all the fires will go out.”


CATEGORIZED UNDER: Space & Physics, top posts
MORE ABOUT: physics
  • Argent

    Clearly, magic is involved in the strength and stability of the Wall. No problem.
    But what is the actual needed temperature for the (non-magical) stability?
    -40°C = -40 °F, not -104 °F (which is -75.6 °C).

  • Icabod

    Convient plot twist or magic, or both. Whatever.

  • Uncle Al

    Project Habakkuk and pykrete. No problem.

    • Erik Bosma

      The whole show is practically based on the premise that energy can be created from nothing and is also an endless resource. In order for me to engage even the tiniest amount with a story. I demand that the author has done at least a minutiae of research. Even an iota. Anything??

      • Debanjan Dey

        You’re watching the wrong genre obviously.

        Any example of a fantasy production that prioritizes adherance to laws of physics?

  • Tone Lacy

    If magic is preventing the walkers from passing through then how why were they able to bring that one Walker to the South for the meetings at Kings landing?

    • Jerald W. Olp Jr

      That was not a “White Walker”, but a wight. There’s a difference. The White Walkers were created by magic by the “Children of the Forest.” Weights are there victims, or reanimated dead.

      • Tone Lacy

        Thank you for that

      • marco esquandolis

        Yeah, what he said. There’s a difference. Just like (in the books at least. Not sure if the show gets in to this) the obsidian. It kills the White Walkers easily, but in the books when Sam tries to use it on a wight it doesn’t do anything.

  • Christos Fotinakos

    Its endurance relies upon a macro quantum entanglement affect utlizing the Zeno effect.

  • Erik Bosma

    Well what kind of trash do you expect to come from the soap opera addled brain of George R. R. Martin. I think I might copy as many of the more famous scenes in history I can find, weave them together with the script from All My Children, change my name to Erik R. R. Bosma and start the gore porn and violence porn (oh, that pretty little girl burning to death as she screamed for her mommy was a stroke of genius – NOT!) and just regular T and A (and a few Peepees thrown in for the ‘ladies’) porn engines revving up as high as I could get it by the censors too. Maybe he can join forces with the Harry Potter ‘genius’ and bore us to death for the next 50 years. Wasn’t the 20th century bad enough?

  • David Chile Uba

    New episodes please; no business with laws of thermodynamics, just enjoying the story. Who cares about how the wall stands?

    • Vincent Salvatore

      Um….a science magazine?😉

  • WT Smith

    The books are explicit that they use gravel. Nothing says that the wall isnt further reinforced with bracing or timbers.

  • marco esquandolis

    There’s def magic built into The Wall. It gets mentioned many times in the books. The most notable of which is in Dance during the Mel POV chapter where she talks about the fact that all her spells become amplified when she’s there.

  • RCDavis

    How does Discover magazine fail the Celsius to Fahrenheit conversion?

    That’s a pretty fundamental error…

    • Kurt S

      It appears they used a app converter and forgot to but in the negative. Because 40°C is 104°F. Whereas -40°C is -40°F. It is an unfortunate mistake, one that I hope is rectified.

      • RCDavis

        Good catch! So now we know *how* the author, Nola Taylor Redd, did it. It’s STILL a pretty glaring error though, and two days later still not fixed.

        If they aren’t going to employ an editor, wouldn’t it just make sense as standard practice to scan the comments the next day where obvious errors (like this one) are sure to be called out?

  • TWAndrews

    -40° C = -40° F, not -104° F

  • Daniel Johnson

    Future-seeing kids with a spiritual link to trees, walking skeletons, dragons, and irradiated explosives I’m all fine with, but this ice physics story just makes me sick HBO! #it’sadocumentary


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