Scenario: ElectroMagnetic Pulse (EMP) and Solar Flares

February 7, 2013

in Negative Events

The term ElectroMagnetic Pulse (EMP) is mostly used to describe a strong electromagnetic wave or pulse that accompanies a nuclear explosion. Solar flares can also produce similar electromagnetic waves. Both threat scenarios will be discussed here, with some analysis of similarities and differences.

Electromagnetic (EM) waves induce current in conductors, like wires and metallic objects. When a radio wave impacts an antenna wire, it induces current to flow in the wire, which is then amplified to provide a useful version of the radio broadcast. When a strong EM wave impacts a conductor, it induces a stronger current. EMP is a massive wave that can induce enough current to not only destroy delicate electronic circuits but also to damage much cruder conductive objects, such as power lines. Solar flares or “geo-magnetic” storms can also produce strong EM waves that have potential to disrupt electrical and electronic devices.

EMP THREAT
A typical EMP threat scenario involves a single high altitude nuclear weapon detonation that exposes a large amount of territory to an electromagnetic pulse. Several weapons could be used, but it is possible to blanket the entire north american continent with a single weapon. A nuclear bomb releases a blast of gamma radiation and when the gamma rays hit the top of the atmosphere, they strip away electrons, creating a massive wave or electromagnetic pulse. The pulse spreads out to a range determined by the altitude of the nuclear blast. At an altitude range of 250 miles or higher, the EMP covers a diameter equal the United States. The blast effects and radiation are not of any other consequence at this height. It is the EM wave that does the damage. It is also possible to create non-nuclear devices that produce an EMP, but their range tends to be much smaller.

SOLAR FLARE THREAT
Solar flares and Coronal Mass Ejections (CMEs) are two different kinds of solar activity that are often associated with each other. They each have the ability to create a wave that can cause a geo-magnetic storm, disrupting our infrastructure. Solar flares typically take 1-2 days to reach us, while CMEs take 1-5 days. Bursts of protons can reach us in under an hour. Solar flares and CMEs are happening all the time on the Sun, but unless they are directed at Earth, they may have no effect at all on us.

DAMAGE
Damage from an EMP is dependent upon the distance the wave has to travel, the strength of the wave, the frequencies generated in the wave and any protections that are in place or interfering objects that act to shield a device that might sustain damage. Longer wavelength frequencies are more casually intercepted than shorter wavelength frequences, but nuclear detonation generated EMPs produce wavelengths of all frequencies. It is more likely that the amount of damage created will be determined primarily by the power of the wave.

Nuclear sourced EMP creates three distinct energy events:

  • E-1 – lasts up to one microsecond, is similar to high energy static charges, is high frequency, will likely burn out many protections (such as surge supressors) because of suddeness of the event, with no build up for warning, exists in all nuclear explosions regardless of the size of the warhead
  • E-2 – lasts up to one full second, is similar to a lightening strike, could be protected against by good surge suppression, but that defense will likely have been destroyed by E-1
  • E-3 – lasting from several seconds to several minutes or longer, similar to a geomagnetic storm caused by a severe solar flare, is low frequency (1Hz or less), affects long lines more and is proportional to the size and strength of the nuclear warhead (E-1 is not)

It is difficult to determine with certainty the extent of damage that a nuclear EMP can cause. In 1963 a test ban treaty ended above ground and atmospheric testing. At that point, little attention was being given to EMP effects. What we know about EMP today comes from data collected before the test ban treaty and simulations run on supercomputers. Since this simulation data is at least partially classified, public knowledge in the area is sketchy.

It is possible that a single high altitude nuclear EMP could wreak havoc with both electronic and electric devices over a wide area. In a worst case scenario, the E-1 wave could destroy any unprotected electronics and strip away normal protections leaving any surviving equipment vulnerable to the following E-2 wave. The E-3 wave could melt power lines, destroy transformers and damage any common electrical equipment that can act as an antenna for the long waves.

An important consideration for this scenario is that most if not all electrical infrastructure could be damaged or destroyed and the ability to repair and replace equipment would be delayed greatly. Backup components that are normally stored without any special shielding to protect them would also be damaged. It’s a fair assumption that some infrastructure designated as critical by government and military might have backups that are safely protected with shielding. It’s also a fair assumption that most civilian infrastructure will be far less protected and take much longer to recover.

Most water and natural gas supplies are replenished by electric pumps. Fuel depots rely on electric pumps to move fuel to and from vehicles. Petroleum refineries depend upon public utility electric power as do water treatment plants. Railroad locomotives, trucks and automobiles that are older may exhibit some resistance to EMP, but more modern vehicles that depend more upon electronic components are likely to be disrupted in some fashion. Communications and control systems in the power grid and transportation areas will be disrupted. Commercial aviation is likely to be shut down in the short term and many flights in the air during an EMP may not be able to land safely. Agricultural systems are highly dependent upon the other infrastructures listed above and will be severely impacted until recovery begins.

Urban water supply will be the most critical failure. Water supply towers are often designed to hold about twenty four hours of water under normal usage demands and depend upon electric pumps to constantly refresh the level. Without power, water will begin to lose pressure and become unavailable within a day or two. Few households have water reserves beyond 2-3 days. 2-3 days with no water causes severe dehydration, mental disfunction and death. After a week without utility water, death from dehydration could become commonplace. The breakdown of sanitation processing will contribute to surface water becoming contaminated at the same time as many people resort to drinking from it. This will cause widespread disease and there will be little or no medical response available.

Damage created by a solar flare is also highly unpredictable, but is likely to be similar to the E-3 wave that can disrupt over a longer time period with lower intensity. This wave tends to induce current in very long conductors and has been known to melt power lines and cause fires in telegraph equipment and railroad ties as high amperage is built up over a much slower time frame than E-1 or E-2. If the E-3 wave from a solar flare takes down our entire electric power grid, we still have to deal with all the ripple effects into other areas, even though sensitive electronics may not be affected.

RISK ASSESSMENT
A direct EMP attack from a nation that has nuclear weapons is unlikely because of the threat of retaliation. But that inhibition fades if a smaller group obtains a weapon and the means to deliver it. Missile systems capable of lifting a nuclear warhead to the desired altitude are available. Most missile defense systems are designed to stop incoming threats. An EMP attack missile launched from near the border of or even inside the target area would only take a few minutes to reach altitude, would be moving away from any pursuing defensive missile (instead of incoming) and the nearly vertical outbound trajectory might not be perceived as a threat in time to react defensively. It is impossible to predict accurately the possibility of a nuclear EMP attack, but if one occurs, the damage could be severe, widespread and might involve a long and difficult recovery. There is likely to be little or no warning.

The damage from a strong solar flare is likely to be milder (this too is an unknown) but the likelihood of occurrence is near certainty.
We don’t know ahead of time when a solar flare will happen, how strong it will be, how long it will last or how directly it will hit Earth. But astronomers monitor solar activity regularly and dangerous flares are usually observed many hours and even days before they reach Earth. We should get some warning.

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