The legacy of nuclear bomb testing in the landscape: not all terrestrial craters are formed by meteorite impacts
Some regions on Earth are extensively pockmarked by craters — but these were not formed by meteorite impacts. They are a legacy of decades of nuclear bomb testing (see map). Since 1945 — the year of the first atomic bomb test, Trinity — more than 2,000 nuclear tests have been conducted by nuclear-armed states. From land to seafloor, landscapes hold the record of these devastating blasts.
The formation of craters from nuclear weapon testing informed part of the theoretical and experimental work on impact cratering mechanics in planetary science that had begun in the first half of the 20th century. However, we should never forget that nuclear testing goes hand in hand with physical and ecological destruction, the uprooting of native peoples from their lands, and radioactive contamination of air, soil, and water — consequences that continue to devastate communities today.
Bikini and Enewetak Atolls — in the Marshall Islands archipelago — symbolise the dawn of the nuclear age. The United States chose Bikini Atoll as a nuclear weapon testing site immediately after the Second World War. It is home to the Bravo crater, generated by the most powerful thermonuclear weapon ever tested by the USA. The nearby Enewetak Atoll was also designated as a test site, where the first H-bomb was detonated. At the end of the 1970s, the Runit Dome — a concrete structure — was built on the atoll to contain radioactive debris.
Many craters were generated by underground blasts, following the 1963 Limited Test Ban Treaty signed by the US, Soviet Union, and UK, which prohibited atmospheric, underwater, and outer-space testing while permitting underground tests. Craters formed by underground explosions are subsidence craters — the surface collapses into the cavity left by the blast. The Sedan crater in Yucca Flat, Nevada, is the largest human-made crater in the USA, created in 1962 as part of a programme investigating the use of nuclear weapons for civilian purposes such as mining.
Another heavily exploited area is the Semipalatinsk Test Site in Kazakhstan, the primary testing ground for the Soviet Union. Beyond weapons testing, the Soviets also ran a programme using nuclear explosions for earth-moving purposes — creating artificial lakes, harbours, and canals. In 1965, the Chagan crater was formed by a nuclear blast at the confluence of two rivers, which flooded to create a lake that remains radioactive to this day.
The following articles discuss the devastating impacts of nuclear weapon testing on native populations and communities at the three sites mentioned above: