There are obviously a few things Bran the Builder didn’t account for when he was raising the immense frozen barrier that was supposed to keep out wildlings, wolves, giants, ice zombies, and things possibly worse than ice zombies in Game of Thrones. Glaciologist Martin Truffer believes there are few things other than magic that could keep this wall defending the northern border of the Seven Kingdoms for 8,000 years.
You may remember Truffer first seeing through the magic back in 2013, when he determined that there was no way a wall 700 feet tall, 300 miles wide and 300 feet thick would survive for that long. He still argues that there is no way an ice barrier that immense could still be standing in his study The practicality of defensive ice walls: How would the great ice wall in Game of Thrones hold up? which he recently presented at the annual meeting of the American Geophysical Union. This time, he must have crept into the vast library of the Citadel to unearth even more.
Imagine there were no ancient spells holding this thing up for so many centuries. The problem with ice is that it flows, and the amount of stress needed for glacier ice to flow is just a fraction of what The Wall would generate at its base —if you can even fathom 261 pounds per square inch—meaning it would collapse much sooner than any Maester would want to believe.
Truffer figured that the forests (and creatures) around the Wall mean it can’t be cold enough to mummify everything in ice. He put the average temperature at about 14 degrees Fahrenheit, which would see the Wall collapsing into itself within months or even days.
This would probably sound like blasphemy to the Night’s Watch and anyone else who would rather not have a limb chewed off or be turned into a White Walker. Even Castle Black has nothing on the hordes of frozen undead just waiting to add more of the living to their ranks.
Before everyone gets eaten, Truffer believes there are a few ways to keep the Wall standing just long enough to evacuate everyone before inevitable doom crashes down. Ice slopes buttressing it would hold off collapse, but also give an assist to ravenous things with teeth that craved human flesh. There would be also be a hundred times less stress on the wall if it was plunged into a deep freeze of about -40 degrees Fahrenheit. That gives the armies of Westeros several years to steel themselves against the impending zombocalypse.
Even Truffer had to concede that the only thing which could possibly keep the Wall upright are the spells that Sam revealed could also be acting as zombie repellant. However, this research could give us a better understanding of polar ice caps on Mars, and that is otherworldly.