Incredible footage of nuclear explosion testing during the Cold War declassified in the US

Previously classified footage of nuclear explosions tested during the Cold War have been rescued from high-security vaults and released by physicists in the United States.

The massive and terrifying explosions in the Nevada desert and Pacific region were captured on film between 1945 and 1962, but the footage has been buried in vaults in the US ever since.

A team of physicists at the Lawrence Livermore National Laboratory (LLNL), in California, hunted down these films, rescued them from decomposition, and painstakingly reanalysed and declassified them for public release.

"It's just unbelievable home much energy's released," weapon physicist Greg Spriggs said on the LLNL website.

"We hope that we would never have to use a nuclear weapon ever again. I think that if we capture the history of this and show what the force of these weapons are and how much devastation they can wreak, then maybe people will be reluctant to use them."

The US conducted 210 atmospheric nuclear tests during the Cold War era. Multiple cameras captured each event resulting in around 10,000 films, LLNL said.

Physicists at LLNL hope to preserve the contents of the films to provide better data to post-testing-era scientists.

To date, the team has recovered 6500 films, but only 750 have been declassified.

"You can smell the vinegar when you open the cans, which is one of the byproducts of the decomposition process of these films," Spriggs said on the LLNL website.

"The data we're collecting now must be preserved in a digital form because no matter how well you treat the films, no matter how well you preserve or store them, they will decompose. So this is it.

"We got to this project just in time to save the data."