During World War II, the United States and New Zealand tested a "tsunami bomb" that could potentially create a 33-foot wave capable of inundating a small city, The Telegraph reports.
The British newspaper says the tests involved a series of 10 large offshore blasts. The top-secret operation, called Project Seal, involved around 3,700 bombs that were detonated first in New Caledonia and later at Whangaparaoa Peninsula, near Auckland.
The Telegraph says details of the project were discovered in military files in the national archives by Ray Waru, a New Zealand author and filmmaker.
He found that the project was begun in June 1944 after a U.S.naval officer noted the power of large waves created by explosions used to clear coral reefs around Pacific islands.
Waru, who writes about the project in his new book Secrets and Treasures, says the tests were positive, but the project was shelved in early 1945, although New Zealand continued to produce reports on the experiments into the 1950s.
The Telegraph says experts concluded that a successful tsunami bomb would require about a million pounds of explosives arrayed in a line about five miles from shore.