How Long Will an EMP and its Aftermath Last

EMPs: Electromagnetic Pulses. To many preppers, EMPs are seen as the penultimate doomsday event. Be they a naturally occurring phenomenon or the byproduct of man-made superweapons, EMPs are theorized to knock humanity back to an Industrial Age state of being in a literal blink, or perhaps even worse.

By disabling or destroying any electrical device that utilizes a circuit board, an EMP will eliminate virtually every unhardened piece of modern technology. What preppers want to know is how long it will last?

An EMP is both an instant occurrence and an aftermath: EMP itself radiates outward from its source at nearly the speed of light. These waves will interact will electrical devices and inflict damage nearly instantly.

The duration of an EMP aftermath is highly variable depending on severity. Light damage can be repaired in days or weeks. Severe or widespread damage might take years or a decade or more to replace.

Complications

There is more to consider than just the EMP “burst” and its effects, since some weapons that generate EMPs as a secondary effect, like a nuclear warhead for instance, will “sow” electromagnetic interference in the form of nuclear fallout, the “radiation” component of this fallout being, you got it, radio waves.

This manifests as continual disruption of devices that receive or transmit radio waves, and potentially can interfere with solid state electronics like the main pulse.

This effect will be present until the radioactive material has gone though several phases of its half-life or it is cleaned away entirely. Again, replacement or repair of affected electronics will be required.

So while EMPs are typified as a large, wide area event, EMP effects can take several forms and the duration of each is dependent on its nature.

Survivability

The only way to protect functionality is to specially harden the device against EMP by design, an expensive and, frankly, theoretical proposition since most electronics have not been tested against an EMP of the magnitude which is likely to cause a regional or national crisis.

“Isolation” of sensitive electronics is possible with Faraday cages, but again this is beyond the reach of nearly all preppers when it comes to proper testing.

One of the only surefire ways of preventing a total-loss of capability from an EMP is to go “analog”. While not entirely true, as electronics utilizing early vacuum tube technology are practically immune to an EMP.

The electrical potential needed to overwhelm and force a vacuum tube’s receiving plate to feed power in reverse is astounding, and any EMP that is generated close enough to the vacuum tube to accomplish that (one generated by nuclear weapons, at least) would be a moot point since the tube would be destroyed.

The other major factor in determining the duration of an EMP’s practical effects is in the intensity of the pulse itself. An EMP can potentially destroy only the most delicate of electronics, or it can pop fuses and trip circuit breakers. It is capable of being so strong it literally immolates power lines and vaporize conductors. It all depends on its strength.

A comparatively minor EMP may only result in a bunch of burned out consumer electronics heading for landfills. Anything protected by a circuit breaker or fuse and not containing a computer chip should survive and be ready to go when the fuse is replaced or the breaker reset.

Anything subjected to a strong enough EMP that slags conductors and fried electrical systems and circuit boards alike will the stuff doomsday is made of; there is no telling how long it would take to repair such catastrophic damage over so wide an area.

Conclusion

While an EMP is itself over in a millisecond, its effects can persist for weeks or months in the form of radioactive fallout if it was generated by a nuclear detonation.

The damage caused by an EMP will in effect render the world a snapshot to its silent and invisible havoc; depending on the strength of the EMP, anything from minor repair to complete overhaul and replacement of all affected electrical systems may be required, taking years or even a decade or more to fix.

Tom Marlowe grew up with a gun in his hand, and has held all kinds of jobs in the gun industry: range safety, sales, instruction and consulting, He has the experience in helping civilian shooters figure out what firearms work best for them.

I don’t know your background or where you got the information for this article; but, you’ve gotten so many facts wrong I have to take them on and explain them; however, to be honest, not many people have the physics background to understand or really explain an EMP.

I’ll add more here later today as I get iime.

There are no EMP’s that originate from a naturally occurring phenomenon and although a CME (Solar Coronal Mass Ejection) can have similar effects, they are limited to long lines (antennas) like power and communications infrastructure and are unlikely to affect any electronic device not connected to a long wire antenna or the power grid.

The major difference is the frequency (rise time) of the generated pulses.

Actually, most small consumer devices are hardened more than people know.

They have to endure ESD, that spark from your finger when you walk across the room and also interference from the radio waves emitted from many other consumer devices, like fence chargers, neon lights, LED light bulbs and some HDTV’s.

That is true in some instances; but, not all devices in all cases, since it depends on the type of circuit board in the device, the type of case, what kind and how much ESD protection is in the design, and the orientation of the device to the incoming EM wave front.

Severity will again depend on the device, its orientation, and how much conductive material is there to “receive” the energy.

I think that most of my systems, including my generator has a good chance of surviving; but, the biggest effect on long term duration and down time, will be the power grid, since it has thousands of miles of power lines to act as antennas that will collect the energy from a pulse and damage the infrastructure, including high voltage switch gear and transformers, some of which are custom built and too large and expensive to be kept in stock.

Anything you have plugged into the power grid during and EMP is also likely to be damaged.

Complications

The radiation components of fallout are definitively not radio waves; but, a combination of Alpha & Beta Particles and Gamma Rays, with the Gamma being the only EM radiation.

If the Alpha, Beta, and Gamma are of sufficient intensity (ionizing radiation) they can ionize the air around them and ionized air can emit radio frequency noise, like that hears on an AM radio during a thunderstorm.

That radio noise is also what remote lightning detectors use when you see the meteorologists showing lightning activity maps.

This manifests as continual disruption of devices that receive or transmit radio waves, and potentially can interfere with solid state electronics like the main pulse.

No it cannot. See the explanation above.

It can interfere with radio communications; but, has nothing to do with solid state vs. vacuum tube based equipment. I have both and see & hear this clearly during thunderstorms, both local and remote.

This is correct; but, once again, the residual radiation from fallout will not damage undamaged or functional equipment, only cause radio frequency interference

Survivability

This really depends on the device. While most consumer devices are not tested against an EMP specification, they are compliance tested for FCC emissions (a two way function) and for ESD, so small devices unconnected to outside wiring (power lines, cable TV, telephone lines, etc) are likely to be undamaged,

“Isolation” of sensitive electronics is possible with Faraday cages, but again this is beyond the reach of nearly all preppers when it comes to proper testing.

A good faraday enclosure for a single device is easy and rather foolproof. Place the device in a cardboard box, with the original container often being the best fit.

Wrap the box with several overlapping layers of aluminum foil in one direction, Tuck in the foil sticking out around the box, and then wrap the side of the box with cardboard still showing. Ticj this vox on a shelf or in a srawer.

Analog? What does that even mean? I use both solid state and vacuum tube equipment with both analog and digital communications.

If you actually meant using vacuum tubes, they would be mostly immune to the EMP effects; but, be prepared to have lots of power available, since they are often heavier, use much higher voltages and currents to operate, generating a lot of heat in the process. The weight and power are one reason that solid state electronics have overtaken them.

OTOH, tube type equipment is durable. I gave some Equipment I built back in the 1970’s that had not been operated in a decade to a friend who is a new ham. He connected it and it was still operating like new.

Destroyed along with its owner and the building where they were hiding due to heat and blast effects of the weapon.

It is not likely to vaporize conductors; but, circuit breakers and fuses within the power grid may all be subject to tripping &/or failure.

Wow. You don’t seem to understand the rise time of an EMP pulse, that will go right around / through fuses and breakers before they can trip.and can still cause damage, The best option is still to not have equipment connected to outside antennas, like the power grid, cable TV or telephone lines.

Conclusion

While an EMP is itself over in a millisecond, its effects can persist for weeks or months in the form of radioactive fallout if it was generated by a nuclear detonation.

True; but, once again that fallout, while dangerous to living creatures, is unlikely to cause any additional equipment damage, once it is functional.

Unconnected small items may easily survive; but, the power grids (there are 3) as a national energy provider will likely be damaged and take months or more to repair.