Most often when we think about exercise we think aerobic. That is in part because of the high energy classes available at most gyms. Aerobic exercise is not confined to those classes, however. For most people, low to moderate exercise or exertion is generally aerobic.
The biggest iron mine. The worlds biggest open pit iron mine can be found near Hibbing, Minnesota. At its maximum, the area covered by the Hull Rust open pit mine is five miles (8km) long, 2 miles (3,2km) wide and 535 feet (180m) deep. It looks like a man-made Grand Canyon of over 2,000 acres (8,1kmÂ²).
The deepest mine. Bingham Canyon Mine, located near Salt Lake City, is the world's deepest man-made open pit excavation. The mine is 2.75 miles (4,5km) across and 0.75 mile (1,2km) deep. Since mining operations started in 1906, Bingham Canyon Mine has been the granddaddy of all copper mines.ingham Canyon Mine, located near Salt Lake City, is the world's deepest man-made open pit excavation. The mine is 2.75 miles (4,5km) across and 0.75 mile (1,2km) deep.