Building on sand

摘要

Each tyre on the massive trucks carting gritty black go o around a mine in northern Canada weighs as much as four cars, an engineer explains excitedly; the trucks, in turn, can carry 400 tons. They are driving around a hole in the ground that is several hundred metres deep, several kilometres wide, and growing fast. Open-cast mines like this are planned for some 3,000 square kilometres of the surrounding area, and subterranean ones beneath a further 35,000 square kilometres.