what is the typical blast radius of a modern nuclear weapon?

Answer 1

a typical thermonuclear weapon ( hydrogen bomb ) averages about 20 megatons. this type of weapon is used to destroy entire cities.

in such a weapon, everything ( including metals ) is vaporized within 5-10 miles.

almost everything is burned to the core within the next 20 miles.

the next 20 miles sees unburned items destroyed from the shockwave.

direct radiation burns can be noted up to 50 miles in living tissue.

airbone contamination ( fallout ) can affect regions as far as 100 miles or more depending on wind patterns.

warm air from the intense heat can be felt as far as 300 miles.

the mushroom cloud can reach as high as 60,000 ft or more ( 20,000 ft higher than jetliner.)

"EMP" or electromagnetic pulse can destroy electronic devices over 1000 miles away .

i hope i was able to shed some light about the power of modern nuclear weapons :)

Answer 2

The typical (most used) nuclear weapon is the B61 bomb. They can go to 340 kiloton. The bombs on Japan were 21 and 15 kiloton.
With 2.5 kiloton, you have a death circle of 1 km.
With 20 kiloton by far the most life is burned to death within a radius of 40 km.
With a 1 megaton bomb you get a 2500 km. radius.
That's all excluding the fallout / radioactive pollution, which goes globally and a higher background radiation is the result (which is already measurable globally, as a result of all bomb tests and nuclear plant usage in the past).

There are enough nuclear weapons on Earth to wipe out mankind many thousands times.

http://nuclearweaponarchive.org/Nwfaq/Nfaq5.html

Answer 3

It is unclear what is meant by blast radius. If you are talking about the area where the peak overpressure is sufficient to severely damage or destroy a building, it varies from a mile or two for a Hiroshima-sized device, up to many miles for a larger one. (Radius goes as the cube root of the explosive yield.) The Hiroshima bomb had a yield of around 14 kilotons; most weapons in arsenals today range upward to a few hundred kilotons. Larger weapons have been built, but the increased size is uneconomic: it is cheaper to blast a large target with several smaller weapons than with one large one (because of the cube root rule mentioned above).

Answer 4

Modern nuclear weapons vary from a few kilotons of TNT for "tactical" weapons to about 30 megatons for a large thermonuclear device. That's a variation by a factor of 10,000. The small ones will kill everyone within about a kilometer, the big ones will kill everyone within about 50 kilometers.

Answer 5

About 600 megabooms.