A closer look
Canada is literally bouncing back from the last Ice Age, and it refuses to be rushed. During the Pleistocene, a slab of ice two miles thick sat directly on top of North America. The unimaginable weight of billions of tons of frozen water literally dented the Earth's crust, shoving the viscous, semi-molten rock of the mantle out of the way. Now that the ice has completely melted, the crust is relieved of that crushing pressure. Like a severely abused mattress slowly regaining its shape, the deeply indented bedrock is rebounding as the incredibly sluggish mantle rock creeps back into place deep underground, constantly rewriting modern GPS coordinates.
