Therein lies my insignificance.
This is an instance where size does matter: the larger the nuclear explosion, the larger the affected area. While technical reports and papers on EMP from nuclear detonations are mostly classified, there is a paper by D. Hafemeister of California Polytechnic Institute that provides sufficient detail to derive a simple rule of thumb on the relationship between affected distance and nuclear device yield. The paper makes some simplifying assumptions:
- The detonation is spherically symmetric (which may not always be the case);
- The Earth’s magnetic field is not accounted for;
- Prompt gamma rays account for 0.3 percent of the total energy of the explosion and are emitted within the first 10 nanoseconds of detonation;
- About 0.6 percent of the prompt gamma rays produce relativistic electrons that constitute the E1 component of the EMP; and
- The electric field damage threshold is 15,000 volts/meter or higher in the E1 component.
Plugging in the numbers and presuming these assumptions are appropriate, the rule of thumb is surprisingly simple: D = Y, where D is the maximum damage distance expressed in kilometers and Y is the yield of the blast in kilotons. So, a 20 KT bomb detonated at optimum height would have a maximum EMP damage distance of 20 km; a 1 MT (1,000 KT) bomb would damage out to 1,000 km. The largest North Korean test to date has been estimated to be about 20 KT.
Conclusions
Considering the physics behind EMP and the status of North Korea’s nuclear program to date, doomsday headlines in the press regarding the North’s potential EMP threat are grossly overstated.[4] North Korea’s nuclear tests have not yet demonstrated sufficient yield to cause damage to large areas through EMP. Moreover, with only a limited arsenal, it would not make sense for the North Koreans to conduct nuclear tests simply to develop EMP weapons.
Dunno.
EMP ? Bring it. Perhaps they will finally resume the proper motoring speed and stay in their lane. I survived Y2k, Michael Jackson, Starbucks, and Barry Soetoro. I am determined to survive NORK EMP.