Surreal Footage on Instagram: "In 1971, the U.S. conducted its largest underground nuclear test on Amchitka Island, Alaska, known as Project Cannikin. This 5-megaton explosion, detonated nearly a mile underground, was intended to test a warhead for the Spartan anti-ballistic missile system. The blast caused the ground to lift 20 feet, creating a crater over a mile wide and 40 feet deep. It also generated a seismic shock equivalent to a magnitude 7.0 earthquake. Despite concerns, no major earthqu