Here is the declassified film of from the show Trinity and Beyond of a 15 megaton thermo nuke going off in 1954. It was suppose to be only 6 megatons or twice as big as Hiroshima. For the record Russia is said to have at least 50 megaton nukes.
https://www.youtube.com/watch?v=Ge865CR9pN8
Here is something I’ve had fun with for well over a decade. It’s updated. You can pick any place on google maps, pick your bomb, and nuke it. It gives all sorts of variable options: air burst, ground burst, fallout from prevailing wind, etc.
It lets you know what a nuke would do to the area. One of the most fascinating things it demonstrated to me was just how small the WWII bombs really were. The reason everything was leveled is that it was all made out of wood and paper.
https://nuclearsecrecy.com/nukemap/
“It was suppose to be only 6 megatons or twice as big as Hiroshima.”
Little Boy, the Hiroshima bomb was nowhere near that powerful. It’s estimated it was about .013 to.018 of one megaton. The most powerful nuke in our arsenal today is about 1.2 megatons.
https://en.wikipedia.org/wiki/Nuclear_weapon_yield