SAN FRANCISCO (AP) — Scientists have rediscovered a mostly intact World War II aircraft carrier used in atomic bomb tests and then sunk off the Northern California coast decades ago.
The National Oceanic and Atmospheric Administration located and recorded video of the USS Independence as part of a mission to map an estimated 300 historic shipwrecks in the waters outside San Francisco's Golden Gate Bridge.
Images captured by a remotely controlled miniature submarine showed the Independence sitting upright about 30 miles off the coast near the Farallon Islands. A plane is visible in a hangar.
The Independence operated in the Pacific during the war and served as a target ship for two Bikini Atoll atomic bomb tests in 1946.
"This ship fought a long, hard war in the Pacific, and after the war, was subjected to two atomic blasts that ripped through the ship," NOAA scientist James Delgado said.
Despite the damage incurred, the Independence continued to float. The Navy used the ship to study nuclear decontamination while it was moored in San Francisco.
The Navy towed the Independence out to sea in 1951 and scuttled it out of concern the damaged ship would sink near the city.
The military branch kept the site of the ship's sinking secret.
The contamination poses little danger to public health because of the ship's isolation 2,600 feet underwater and 30 miles from the coast, scientists say. Neither the submarine nor tools used to examine the ship showed any signs of increased radiation, Delgado said.
Kai Vetter, a University of California, Berkeley, nuclear engineering professor, said the ship posed a serious risk to workers at the San Francisco shipyard where the ship was moored after the atomic tests.
"But the risk to the public now is extremely small," Vetter said. "Water is a very efficient shield."
Delgado said: "This ship is an evocative artifact of the dawn of the atomic age, when we began to learn the nature of the genie we'd uncorked from the bottle.
"It speaks to the 'Greatest Generation' — people's fathers, grandfathers, uncles and brothers who served on these ships, who flew off those decks, and what they did to turn the tide in the Pacific war."
Delgado said he doesn't know how many drums of radioactive material are buried within the ship — perhaps a few hundred. The barrels were filled with concrete and sealed in the ship's engine and boiler rooms, which were protected by thick walls of steel, Delgado said.
Still, word of the Independence survey stirred up lingering concerns about the nuclear waste near the Farallon Islands.