This page shows a simulation of the 20 kt nuclear bomb (20 kt) detonated over Trinity site, NM, USA (1945). The map displays the estimated fireball, the zones of heavy, moderate and light blast damage, thermal radiation and ionizing radiation. Click «What does that mean?» for a detailed legend, or run your own detonation on the main page.
Trinity, 16 July 1945
The first nuclear explosion in history took place at 5:29 a.m. in the Jornada del Muerto desert of New Mexico, about 55 km south-east of Socorro. The device, nicknamed the Gadget, was an implosion bomb of the same design as the one dropped on Nagasaki three weeks later. It sat on top of a 30-metre steel tower, so the shot was effectively a low surface burst; the yield is now put at about 21–25 kilotons, several times what most of the scientists had bet on.
The tower vaporised, the desert sand under the fireball fused into a green glass later named trinitite, and the flash was seen from Albuquerque and El Paso. Because the burst was so close to the ground, it produced real fallout: a plume drifted north-east over ranches and small towns, something the planners had badly underestimated. On this map the circles are drawn for an airburst of the same yield over empty desert, which is why they contain no casualties.
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