So… What Exactly Is an Emp? All Its Phases Explained

If you’ve taken it upon yourself to get ready for those disasters and crises that life can sometimes throw our way, you’ve probably heard of an EMP before.

solar flare

In the context of prepping and survival, this is the event that will knock out much of our electrical grid, and destroy any equipment or vehicles that rely on circuit boards and other, similar components.

Seriously worrisome stuff, and depending on who you ask they can be damaging on a regional level or even borderline apocalyptic at the national level. But just what is an EMP anyway?

An EMP, or electromagnetic pulse, is a short burst or pulse of electromagnetic energy. Created by natural phenomena or man-made technology, EMPs can disrupt, damage, or destroy electrical grids and equipment.

When you hear EMPs discussed in the context of a survival situation or catastrophe, most folks are talking about major events that could knock out society or most electronics, but EMPs can actually be really small and relatively weak, too, doing little more than disrupting communication signals or causing electronics to behave erratically.

The proliferation of weapons that can cause massively powerful EMPs, though, means that this is one threat that you must learn about and get ready for. Keep reading and learn more…


The Science Behind EMPs

As mentioned, an EMP is defined as an electromagnetic pulse, and maybe broadly categorized as a type of transient electromagnetic disturbance

However it is created, an EMP typically covers a very wide band of frequencies, ranging from very low to high, specifically excludes infrared, visible, ultraviolet, X-ray, and gamma ranges despite the source.

Because of this wide frequency range, emps might have a visual component in the form of aerial lightning or sparking and arcing from conductive materials, though this isn’t the main threat of the event.

If you were to look at an EMP as a pulse waveform model on a diagram, you would see that it would have a sharp spike, the build-up to the maximum intensity of the EMP, followed by a relatively slow decay. This is the typical form of instantaneous EMPs like lightning strikes, nuclear detonations, and similar “one shot” instances.

However, in the case of EMP generators, prolonged solar activity like coronal mass ejections, and even specific phases of a nuclear EMP, might take place as a succession of pulses, with a form that looks like a rising and falling wave repeated at mostly regular intervals.

The interactions of each wave, or pulse, will have various effects depending on the material or device that is interacting with. If the resulting voltage surge is enough to create a spark, that can start a fire or ignite flammable materials or vapors.

More complicated devices relying on precisely controlled currents will be disabled or overloaded, potentially damaging or even igniting.

Sensitive materials like hard drives, tapes, and magnetic media will be disrupted or completely wiped clean of data. Even more mundane materials like wood could potentially be ignited in the right circumstances by the heat-induced.

Ultimately, the science behind an EMP is relatively easy to understand, but the interactions it has with other materials and technology are incredibly complex.

How are EMPs Created?

EMPs can be created and projected by a wide variety of different phenomena, including natural events.

When it comes to substantial, damaging, or massively destructive EMPs, the two biggest concerns are nuclear electromagnetic pulses and non-nuclear electromagnetic pulses, or NEMPs and NNEMPs respectively.

As it turns out, you don’t only have to worry about the apocalyptic blast and flash of a nuclear warhead: the donation will actually create a powerful EMP as an additional effect by changing electric and magnetic fields.

This will then have negative interactions with all sorts of electronics and various electrical systems, typically in the form of a massive and damaging voltage surge.

A nuclear bomb that is detonated high up in the atmosphere is actually even worse when it comes to creating an EMP, because the gamma rays that are generated will ionize free electrons, and the whole pulse will have a much wider area of effect, even if the effects of the blast are greatly lessened or mitigated entirely due to altitude. Non-nuclear EMPs take the form of a specialized generator-type weapon system, not a bomb.

Other than that, lightning strikes create potent, localized EMPs as can strong electrostatic discharges resulting from friction or other sources. Another EMP source, one that is wildly varying in strength, is a coronal mass ejection, or solar storm.

When the resulting solar winds strike Earth, they can once again cause havoc with electrical systems, and sometimes even cause widespread damage as with the 1859 Carrington event.

Nuclear EMP Phases

Concerning the most likely EMP threats that preppers face today, nuclear EMPs, the pulse will have three distinct phases even though, to us, the event seems to occur basically instantly.

Understanding the discrete phases of an EMP also provides clues into how it can damage vulnerable technology and materials. These phases, broken down into E1, E2 and E3, are detailed below.

E1. Early phase. This is the sharp spike or leading edge of the pulse, producing high-intensity effects over a very wide bandwidth, though it is extremely short in duration.

The E1 component lasts no longer than a couple of microseconds. The E1 component of a nuclear EMP is produced by the emitted radiation interacting with the atmosphere around the detonation.

This is the component of the pulse that typically propagates along power lines, cables, antennas, and other similar conductive materials and induces high voltages and current. Highly likely to severely damage or destroy all electronics and sensitive materials.

E2. Intermediate phase. Also created from the interaction of radiation and the surrounding atmosphere. Significantly longer than the E1 phase, lasting up to a couple of seconds by itself.

Notably, this phase of the EMP is highly similar to the EMP created by natural phenomena like lightning strikes, although there is no attendant current surge as with the E1 phase. This is equivalent to a severe static discharge concerning electronics and other vulnerable assets. 

E3. Late phase. Created by the relatively slow particles propelled by the nuclear fireball interacting with Earth’s own magnetic field. Although relatively weak, this phase can potentially last upwards of several minutes though it could be over in seconds.

Though this is the “weakest” of the phases, it’s the longest lasting and shows a marked similarity to natural EMPs produced by coronal mass ejections and other cosmic activity. That said, it’s considerably more powerful than even the strongest recorded natural event.

The sustained nature of this phase can produce immense current surges across all conductive lines and materials, and is likely to result in overload, overheating, and damage.

Can You See an EMP?

Not usually, though you can often see the source or its interactions with various things, and sometimes see the visual side-effects.

Lightning is one good example, and solar storms can cause visual phenomena akin to the Aurora Borealis in the atmosphere. Potent EMPs can also cause sparking and overheating of some systems.

Obviously, you’ll likely be able to see an EMP that is created by any kind of nuclear detonation, though one that is caused by a specialized generator or other weapon system might likely be invisible and undetectable. You’ll only know it has occurred by the effects it has on the electrical grid and your electronics.

Are EMPs Harmful to People?

To a human being, not typically. The EMP component doesn’t directly affect flesh and blood, be it people or animals though intense magnetic fields can cause mental or visual disturbances in some cases.

As a rule of thumb, even a powerful EMP is unlikely to directly injure humans, but it’s still possible that the strongest, or those with an origin point nearby, can cause harm. If you’re in contact with a conductor during the event, letting go could result in a shock, especially if you move away from it.

Likewise, it’s not impossible that any extremely strong electric field could cause a breakdown of the very molecules in the air and then a dangerous or even deadly arc of electricity.

These effects on humans have not been widely studied concerning nuclear non-nuclear EMPs, but a basic rule of thumb is that any field strength under 200 kv/m will not result in serious injury.

Keep in mind, though, that whatever causes the EMP itself as a secondary effect might well be deadly or very harmful, as in the case of lightning, switching electrostatic discharge, nuclear weapons, etc.

EMPs Can Easily Cause Injury or Death from Secondary and Tertiary Effects

The real problem for people is what the EMP will do to the things we rely on. Vehicles may shut down without warning, computers will turn off, aircraft can go out of control, and vital infrastructure we depend on may be destroyed.

The grid will almost certainly be severely damaged or even totaled outright, bringing society to a screeching halt and sending us back to the Pre-Industrial Age in the blink of an eye.

Refrigeration, life support, water supply systems and so much more that are entirely dependent on electricity and increasingly on computerized control interfaces, will be out of commission or operating at greatly reduced efficiency.

The follow-on effects of such widespread and total damage or disruption will of course place entire regions, maybe even the entire country or large parts of the globe, in severe jeopardy.

How Bad Can EMPs Be for Electronics?

The effects on electronics and electrical systems depend entirely on the strength of the EMP and the sensitivity of the components or system in question to electromagnetic interference and voltage fluctuations.

A minor but still significant EMP might cause computers to malfunction, monitors to flicker, and cause static, popping, or “washout” type interference of communications, be it a cell phone, radio, or something else.

More intense EMPs, or vulnerable systems like unshielded circuit boards, might be overloaded to the point of damage necessitating various components to be replaced before proper function can be restored.

A sustained EMP in the form of a solar storm might also result in a total communications whiteout that is equivalent to ongoing jamming.

Lastly, the most powerful EMPs, especially if the origin is very close to your location, can result in dangerous overload and attendant burnout, causing widespread fires and total destruction that can only be corrected by a thorough overhaul of the electrical grid or replacement of all affected parts.

Some electronics will simply be utterly destroyed and have to be replaced entirely.

What Should You Do to Prepare for an EMP?

Preparing for an EMP is first about protecting vulnerable but essential gear, vehicles, and other possessions, ensuring redundant capability in case of loss, and preparing for the second and third-order effects that will invariably strike society and maybe even the nation in the wake of a powerful and widespread event.

Smaller electronics can be shielded from even potent EMPs by placing them in a Faraday cage, usually in the form of a bag, can, or box that has a fine metal mesh enclosing all sides that will basically intercept the damaging emissions before they reach your electronics.

When it comes to preparing for the aftermath, it’s all about the basics: You’ll need food, water, a generator, tools, and everything you need to sustain yourself and your family for quite a long time, likely.

In the case of equipment that is susceptible to EMPs and difficult to shield, like vehicles, choosing an older make and model that relies less on electronic control means that your ride is less likely to be damaged in the first place, or even totally immune to event.

Vehicles that have only a few such computerized components might be better prepared for the event by having Faraday-shielded spare parts on hand and the know-how to replace them yourself. That will get you back on the road.

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