EMP and its effects were observed during the US and Soviet atmospheric test programs in 1962. Figure 1 depicts the Starfish nuclear detonation—not designed or intended as a generator of EMP—at an altitude of about 400 kilometers above Johnston Island in the Pacific Ocean. Some electronic and electrical systems in the Hawaiian Islands, 1400 kilometers distant, were affected, causing the failure of street-lighting systems, tripping of circuit breakers, triggering of burglar alarms, and damage to a telecommunications relay facility. In their testing that year, the Soviets executed a series of nuclear detonations in which they exploded 300 kiloton weapons at approximately 300, 150, and 60 kilometers above their test site in South Central Asia. They report that on each shot they observed damage to overhead and underground buried cables at distances of 600 kilometers. They also observed surge arrestor burnout, spark-gap breakdown, blown fuses, and power supply breakdowns.
What is significant about an EMP attack is that one or a few high-altitude nuclear detonations can produce EMP effects that can potentially disrupt or damage electronic and electrical systems over much of the United States, virtually simultaneously, at a time determined by an adversary.
Gamma rays from a high-altitude nuclear detonation interact with the atmosphere to produce a radio-frequency wave of unique, spatially varying intensity that covers everything within line-of-sight of the explosion’s center point.
The first component (E1) is a free-field energy pulse with a rise-time measured in the range of a fraction of a billionth to a few billionths of a second. It is the “electromagnetic shock” that disrupts or damages electronics-based control systems, sensors, communication systems, protective systems, computers, and similar devices. Its damage or functional disruption occurs essentially simultaneously over a very large area, as illustrated in the figure below.
Illustrative EMP Effects – Fast Pulse (Figure 2)
The middle-time component covers roughly the same geographic area as the first component and is similar to lightning in its time-dependence, but is far more geographically widespread in its character and somewhat lower in amplitude. In general, it would not be an issue for critical infrastructure systems since they have existing protective measures for defense against occasional lightning strikes. The most significant risk is synergistic, because the E2 component follows a small fraction of a second after the first component’s insult, which has the ability to impair or destroy many protective and control features. The energy associated with the second component thus may be allowed to pass into and damage systems.
The final major component of EMP is a subsequent, slower-rising, longer-duration pulse that creates disruptive currents in long electricity transmission lines, resulting in damage to electrical supply and distribution systems connected to such lines (Figure 3). The sequence of E1, E2, and then E3 components of EMP is important because each can cause damage, and the later damage can be increased as a result of the earlier damage. In the example depicted in Figures 2 and 3, about 70% of the total electrical power load of the United States is within the region exposed to the EMP event.
Illustrative EMP Effects – Slow Pulse Protection and Recovery of Civilian Infrastructures (Figure 3)
History professor William R. Forstchen discussed the potential damage rendered by an EMP (electromagnetic pulse) event, and what we can to do prepare for the possibility. There are actually two kinds of potentials for generating an EMP, military or solar, he explained. A nuclear fission weapon, such as Iran or North Korea are currently developing, that is detonated about 250 miles above the Earth’s atmosphere would trigger electrostatic discharge, striking the Earth’s surface and overloading the power grid and knocking it out, he detailed. The Soviets conducted an EMP test in 1962, and a power plant 500 miles away from the center of the detonation burst into flames, because of the EMP overload that fed into the transmission lines, he cited.
Just a few days ago, we were hit by the largest solar storm in five years, and NASA & NOAA have predicted a significantly increased solar storm cycle over the next 18 months, Forstchen noted. A large enough coronal mass ejection (CME) from the sun could generate a global-wide EMP event, particularly in the northern and southern latitudes. The “Carrington Event” of 1859 blew out telegraph lines, and the “energy output was so intense that railroad ties were bursting into flames,” he said. Forstchen advocates congressional action to protect America’s grid, such as put forth by Cong. Roscoe Bartlett.
William R. Forstchen is a Professor of History and Faculty Fellow at Montreat College, in Montreat, North Carolina. He received his doctorate from Purdue University with specializations in Military History, the American Civil War and the History of Technology. His current book, One Second After was cited on the floor of Congress and before the House Armed Services Committee by Congressman Roscoe Bartlett (R.-MD), chair of the House Committee tasked to evaluate EMP weapons, as a realistic portrayal of the potential damage rendered by an EMP attack on the continental United States.
William R. Forstchen
An electromagnetic pulse (commonly abbreviated EMP) is a burst of electromagnetic radiation. The abrupt pulse of electromagnetic radiation usually results from certain types of high energy explosions, especially a nuclear explosion, or from a suddenly fluctuating magnetic field. The resulting rapidly-changing electric fields and magnetic fields may couple with electrical/electronic systems to produce damaging current and voltage surges.
The mechanism for a 400 km high altitude burst EMP: gamma rays hit the atmosphere between 20–40 km altitude, ejecting electrons which are then deflected sideways by the Earth’s magnetic field. This makes the electrons radiate EMP over a massive area. Because of the curvature and downward tilt of Earth’s magnetic field over the USA, the maximum EMP occurs south of the detonation and the minimum occurs to the north.
In military terminology, a nuclear warhead detonated hundreds of kilometers above the Earth’s surface is known as a high-altitude electromagnetic pulse (HEMP) device. Effects of a HEMP device depend on a very large number of factors, including the altitude of the detonation, energy yield, gamma ray output, interactions with the Earth’s magnetic field, and electromagnetic shielding of targets.
Preparedness refers to the state of being prepared for specific or unpredictable events or situations. Preparedness is an important quality in achieving goals and in avoiding and mitigating negative outcomes. It is a major phase of emergency management, and is particularly valued in areas of competition such as sport and military science.
Methods of preparation include research, estimation, planning, resourcing, education, practicing and rehearsing.
Survivalism is a movement of individuals or groups (called survivalists or preppers) who are actively preparing for emergencies as well as possible disruptions in social or political order, on scales ranging from local to international. Survivalists often have emergency medical and self-defence training, stockpile food and water, prepare for self-sufficiency, and build structures that will help them survive or “disappear” (e.g. a survival retreat or underground shelter).
Anticipated disruptions include the following: Clusters of natural disasters, patterns of apocalyptic planetary crises, or Earth Changes (tornadoes, hurricanes, earthquakes, blizzards, solar storms, severe thunderstorms). A disaster caused by the activities of humankind (chemical spills, release of radioactive materials, nuclear or conventional war, oppressive governments). The general collapse of society caused by the shortage or unavailability of resources such as electricity, fuel, food, or water. Financial disruption or economic collapse (caused by monetary manipulation, hyperinflation, deflation, or depression). A global pandemic. Widespread chaos or some other unexplained apocalyptic event.