How do you make a model of Antarctica?

I would use papier mache or clay on a plywood base. If I were doing it, I would try hard to make elevations to scale as much as possible, and I would try to indicate ice shelves that are not supported by land that is at or above sea-level. I would use the surface of the plywood, of course as sea-level.

I would include a drawing of what the continent would look like if the ice were lifted off. See the link. The picture does not take into account any rise in sea level if the ice melted.

You could even use plaster of Paris to make it. u can do it by adding some p.o.p in a bowl and add water and mix water to become a solid.

then colour it white like snow effect and add some illustrations in it.

if wanted, make models of penguins to keep in it.