File:Fireball comparison pic.jpg

Composite photograph showing the size of two nuclear fireballs over downtown San Francisco. It is worth noting that the heat, radiation, and blast effects would spread over an area many times the size of these fireballs, though.

The larger fireball (the "sunset") has been scaled to the size of a 1 megaton blast (a medium sized hydrogen bomb); the smaller one (in the center) is the size of a 20 kiloton blast (roughly the size of the bomb used on Nagasaki).

Measurements taken from Samuel Glasstone, The Effects of Nuclear Weapons (3rd edn.), (Washington, DC.: Dept. of Defense/ERDA, 1977):
 * 20kt blast fireball 1,550 ft diameter
 * 1 MT blast 7,200 ft diameter

Scaled to picture based on apparent distances between visible landmarks and their real life distances. May not be accurate to the nearest meter but should be close enough to give a sense of scale.

Created by User:Fastfission in Adobe Photoshop, using a PD picture of San Francisco and two atmospheric test pictures (Fizeau and Apache) from http://www.nv.doe.gov/news&pubs/photos&films/atm.htm (which were Public Domain/US Government originally, but heavily modified).

''NOTE: I'm not 100% sure at moment of how accurate this is in terms of the size of their fireballs. Some further calculations of mine seem to indicate they would be somewhat small though their blast damage would be around the size of the fireballs depicted here. Anyway, while I sort this out, don't take this graphic too literally, yet.''