WHAT DOES UNDERWATER NUCLEAR TEST 'UMBRELLA' MEAN?

The 1946 Baker test, just after the chimney had broken in the cloud, and the crack experienced shaped to the drinking water's surface The Baker nuclear test at Bikini Atoll in July 1946 was a shallow underwater explosion, A part of Operation Crossroads. A 20 kiloton warhead was detonated inside a lagoon which was about two hundred ft (61 m) deep.