As a responsible sort, you may be pondering exactly how much anxiety to allot to the recent North Korean nuclear detonation. One cannot, after all, squander angst, 
regardless of the worthiness of a given risk, lest ones remaining capacity for anguish prove inadequate when the next potential catastrophe portends. On the other hand, not putting in enough worry places one in jeopardy of being embarrassed if a disaster actually manifests. And who wants to look silly for not having been sufficiently worried if a nuclear attack takes place? (Not to mention suffering through the inevitable choruses of “I told you so.”)
First, of course, the facts must be quantified.
Admittedly, developing a formula that takes into account such vagaries as the open and covert diplomacy between nations is beyond the scope of this post, and that goes double for determining the Kim Jong-il wackiness factor.
Supplying some basic information that requires nothing more advanced than eighth grade math, however, is a possibility.
Does Size Matter?
According to the New York Times, the North Korean nuclear detonation was “around a kiloton or less.”
Unless one has some context for terms such as “kiloton” - or, I suppose, has experience setting off especially large explosions - this data may not be helpful in gaining a perspective on the size of the blast.
For those who don’t routinely keep track of such things, kilotons and megatons are, in this context, units used to measure energy, especially the destructive energy of nuclear weapons. One megaton, for example, is equivalent to the energy released by the detonation of 1,000,000 tons of TNT. A kiloton is one-thousandth of a megaton and thus equal to 1,000 tons of TNT.
By way of comparison, the same New York Times article notes, “Throughout history, the first detonations of aspiring nuclear powers have tended to pack the destructive power of 10,000 to 60,000 tons — 10 to 60 kilotons — of conventional high explosives.”
For a more dramatic example, the fireball pictured atop this post is a from 23 kiloton test blast fired in 1953 in Nevada. The “Fat Man” bomb, shown below, detonated over Nagasaki, Japan in 1945, had a 21 kiloton capacity
The Wikipedia chart below lists the early American detonations and the first detonation of the other members of the nuclear club. [Click on chart for larger view]
Several handy Nuclear Detonation Effect calculators are available on the internet. The table shown below derives from the ominously named Star Destroyer site, which is, unsurprisingly, a science fiction website. As it turns out, almost all the calculators use the same formulae and produce the same answers.
The impact of a 1 kiloton (0.001 megaton) blast follows:
For anyone interested in a comprehensive and comprehendible discussion of the devastation caused by a nuclear detonation, I recommend Nuclear Weapon Effects
