Topics: Education, Existentialism, History, Medicine, Nuclear Power
21st-century weather models show how radioactive fallout from atmospheric nuclear tests spread more widely than thought across the US
The Trinity Nuclear Test on 16 July 1945 is a key incident in the blockbuster Oppenheimer movie and in the history of humankind. Many scientists think it marks the beginning of the Anthropocene, a new geological era characterized by humanity’s influence on the Earth. That’s because Trinity’s radioactive fallout will forever appear in the geological record, creating a unique signature of human activity that can be precisely dated.
But there’s a problem. In 1945, radioactive monitoring techniques were in their infancy, so there are few direct measurements of fallout beyond the test site. What’s more, weather patterns were also less well understood, so the spread of fallout could not be easily determined.
As a result, nobody really knows how widely Trinity’s fallout spread across the U.S. or, indeed, how the fallout dispersed from other atmospheric nuclear tests on the U.S. mainland.
Today, that changes thanks to the work of Sébastien Philippe at Princeton University and colleagues. This team used a state-of-the-art weather simulation for the 5 days after each nuclear test to simulate how the fallout would have dispersed.
The result is the highest resolution estimate ever made of the spread of radioactive fallout across the U.S. It marks the start of the Anthropocene with extraordinary precision, and it throws up some significant surprises. Some parts of the U.S. are known to have received high levels of fallout, and the new work is consistent with this. But the research also reveals some parts of the US that received significant fallout without anybody realizing it.
The findings “provide an opportunity for re-evaluating the public health and environmental implications from atmospheric nuclear testing,” said Philippe and co.
Between 1945 and 1962, the U.S. conducted 94 atmospheric nuclear tests that generated yields of up to 74 kilotons of TNT. (Seven other tests were damp squibs.) 93 of these tests took place in Nevada, but the first, the Trinity test in the Oppenheimer film, took place in New Mexico.
How The Trinity Nuclear Test Spread Radioactive Fallout Across America, the Physics arXiv Blog, Discover Magazine