World War II “Tsunami Bomb” Back in the News

Auckland, New Zealand – World War II “Tsunami bomb” testing, first revealed when secret documents were declassified 14 years ago, is making news again after a researcher discovered more archived material.

The documents detail the research that Thomas Leech, an Auckland University professor working for the army, conducted to find out what type of explosive pattern might trigger a tsunami. Suggestion of the possibility came from a U.S. Navy officer in 1944 who told the commander-in-chief of the New Zealand Army how he had observed unexpectedly large waves during the blasting of submerged coral reefs.

Testing included dropping thousands of bombs and monitoring their effects around New Caledonia (an important Allied base) and Auckland, New Zealand’s largest city. The stated goal of the tests was to see whether a bomb or series of bombs could generate a tsunami capable of causing major destruction and injury on an enemy coastal city.

Single explosions were found to be “inefficient in the production of waves,” Leech reported in one of the now declassified papers. However, “the use of multiple charges located to conform with geometrical patterns was found to give markedly superior results,” he wrote. He added that that the shape of the charge, the spacing, and the location were all important and that the ideal results occurred when explosions were near to the water surface, rather than at greater depth.

In 1946, American physicist Karl Compton, who served on a secret high-level group advising the U.S. government on the nuclear warfare and was a member of the Naval Research Advisory Committee, visited New Zealand to examine “Project Seal”, code name for the tsunami tests. According to a letter, Compton was “impressed with Prof. Leech’s deductions on the Seal project” and recommended the release of technical data to enable Leech to carry out further study.

Reports were still being produced in New Zealand about the World War II experiments in the late 1950s. In 1961, the U.S. Navy made a request for the final “Project Seal” report to be downgraded from “secret” to “restricted” by arguing that the data would be “extremely helpful” in military studies being carried out.

“Project Seal” is once again in the spotlight because of the release of Secrets and Treasures, a new book by New Zealand author Ray Waru, based on a two-year trawl though the New Zealand government archives.

Ironically, the two allies that worked together on a potential non-nuclear weapon of mass destruction later had a serious disagreement over nuclear policy in the 1980s. New Zealand, long an opponent of weapons of mass destruction, was instrumental in leading the way in trying to develop a weapon that could create devastation they could blame on nature.