Three nuclear bombs to dig a canal

Transcribed from the audio; small errors are possible.

In 1971, the Soviet Union fired three nuclear bombs to dig a canal. The goal send an Arctic River south to refill the shrinking Caspian Sea. The canal would run 112 kilometers. Hundreds of nuclear blasts would dig its middle. This was the test. Three bombs, 15 kilotons each. One kiloton equals a thousand tons of TNT. Buried 127 meters deep and fired together. They tore a trench 700 meters long, but it was only 10 to 15 meters deep, far too shallow for a canal. Radioactive traces crossed borders. The United States and Sweden protested. The canal was never built. Today the crater is a lake with a restricted zone around it. The river still flows north, and it all started with three bombs.