The fireball begins to grow rapidly and rise like a balloon. As the fireball rises and subsequently expands as it cools, it gives the appearance of the familiar mushroom cloud. The vaporized debris, contaminated by radioactivity, falls over a vast area after the explosion subsides thus creating a deadly radioactive fallout with long-term effects. Because of the very high temperatures and pressures at ground zero, the gaseous residues of the explosion move outward. The result of these high pressures is to create a blast wave traveling several times faster than sound. Pressures generated more than 10 Psi with wind speeds more than 800 km …show more content…
This thermal radiation travels outward at the speed of light. As a result, this is by far the most widespread of all the effects of a nuclear explosion and occurs even at distances where blast effects are minimal.
There are two kinds of ionizing radiation created by nuclear explosions, electromagnetic and particulate. Radiation emitted at the time of detonation occurs within the first minutes. Anyone close enough to the explosion to be killed by prompt radiation is likely to be killed by the blast and thermal effects, delayed radiation, which is caused by the decay of radioactive isotopes and is commonly known as radioactive