As an alternative to the atomic bomb, the United States and New Zealand secretly tested a "tsunami bomb" toward the end of World War II that could be aimed at Japan to destroy its small, coastal cities, according to recently unearthed documents.
The tests conducted off New Zealand involved the use of thousands of underwater blasts to trigger large-scale tidal waves. Code-named Project Seal, the top-secret operation was unearthed by Ray Waru, a New Zealand author and film maker, who found files on the tests in his country's national archives.
"Presumably if the atomic bomb had not worked as well as it did, we might have been tsunami-ing people," Waru told The Telegraph.
"It was absolutely astonishing. First that anyone would come up with the idea of developing a weapon of mass destruction based on a tsunami," said Wara. "And also that New Zealand seems to have successfully developed it to the degree that it might have worked."
Launched in June 1944, the project came about as a result of a U.S. naval officer, E.A. Gibson, observing large waves being produced by a series of underwater blasting operations intended to clear coral reefs from around Pacific islands.
Researchers concluded that approximately 2,200 tons of explosives five miles from shore were required to create a wave large enough to severely damage a coastal city.
Tsunamis, large ocean waves that can reach up 1,700 feet in height, are caused by sudden motion on the ocean floor that could be triggered by various events such as an underwater landslide, earthquake, or powerful volcanic eruption.
The 2011 tsunami that killed over 15,000 people in Japan and caused hundreds of billions of dollars in damage, was caused by an 8.9 magnitude earthquake in the Pacific. A 2004 tsunami in the Indian Ocean killed more than 230,000 people in Indonesia, Sri Lanka, India, and Thailand, displaced hundreds of thousands of people and caused billions of dollars in property damage.
According to the government files, the two primary locations for the tests, which included some 3,700 bombs in total, were initially near New Caledonia, an island north of New Zealand, and later off the Whangaparaoa Peninsula, 30 miles north of Auckland.
Though the joint project was shelved by the U.S. in early 1945, New Zealand continued to conduct research on how to produce a tsunami bomb into the early 1950s, according to Waru's findings.