Here's a sanity check: Although ice has a Young's modulus of ~9 GPa when measured by the speed of sound, most practical measurements show it to be more like ~1 GPa in actual structural use. Euler buckling is typically the critical issue in building a tall column (or wall). The critical length of a tall column constrained by Euler buckling is L = .792 * (E/rho)^(1/3) * d^(2/3) where E is Young's modulus, rho is specific weight (density*g), and d is the diameter of the column. If the diameter of the column is ~10 pi feet, then the critical height is ~700 feet. Ice crush strength is ~3.5 MPa, so the pressure at the base of the wall is ~55% of the crush strength. So such an ice wall could barely stand (at least for a little while) on its own. However, I still suspect that it could not resist actual wind loads, and ice has a tendency to creep, and it starts to lose strength above -15 degrees C. So I take my hat off to the Game of Thrones writers -- they either guessed right, or had a structural engineer perform some quick sanity checks. Given that many CGI engineers know a lot about structural mechanics, it's conceivable that the CGI people themselves fed back information to the writers about the max height of the ice wall. At 02:08 PM 11/20/2016, Henry Baker wrote:
The TV series 'Game of Thrones' claims a 700' high ice wall.
Game of Thrones uses significant amounts of CGI, so the only place this ice wall exists is inside a computer.
Nevertheless, could a real ice wall of its dimensions be built and stand?
In various scenes, the ice wall is essentially vertical.
I haven't seen the more-or-less vertical ice walls created by 'calving' glaciers personally, so I don't know whether any of them attain 700' in height.
However, unlike those glacier ice walls, the Game of Thrones ice wall is 2-sided, and is warmer on one side -- enough to 'weep' under the sun.
Sooooo...
Based on standard Earth gravity and standard water ice, is a 700' ice wall possible?
Note that the GoT ice wall is flat, so it doesn't gain any stability from being curved, and as a result, could probably not stand up to the high winds that its mere presence would generate.
Ice is only a tad lighter than water, and 700' is approx. 22x the 32' of water that equals 1 atmosphere.
I don't think that WWII *steel* submarines could withstand 700' depths of water, so the pressure at the bottom of such a wall would be quite high and would likely require some reinforcement.