An electromagnetic pulse is a burst of electromagnetic radiation. EMPs can be either naturally occurring or man-made and can be severe enough to disrupt or destroy the electrical grid and critical infrastructure.
Natural EMPs from Solar Storms
Extreme solar storms created by massive explosions on the sun can create extensive electromagnetic pulses. Such storms occurred in 1859 and 1921, before electricity was in widespread use. A study on the resiliency of the U.S. electric grid published in the 2008 National Research Council report “Severe Space Weather Events” estimated that a great geomagnetic storm today similar to the one that occurred in 1921 could result in blackouts and long-term shortages affecting 130 million people. Other experts disagree on the severity of the possible effects and state that further research is needed. There is, however, agreement that extreme geomagnetic storms could significantly cripple the U.S. electric grid by producing direct current surges in high-voltage transmission lines resulting in permanent damage. In addition, satellite systems, navigation systems, and other devices using electrical components, such as natural gas distribution pipelines, water and wastewater distribution systems, HVAC systems, refrigeration systems, fuel distribution and pipeline systems, computers, telephones and communications systems, and public and private transportation systems, would be destroyed or damaged.
Man-Made Electromagnetic Pulse
Man-made EMPs fall into four general classes.
High-Altitude EMP (HEMP). HEMPs result from a nuclear device detonated fifteen or more miles above the Earth. The effects of the blast depend on the altitude and the strength of the device. One high-altitude weapon could affect the entire continental United States, causing severe damage to the electric grid and communications systems and severely curtailing defensive capabilities. The blast would cause a tremendous power surge of thousands of volts through power lines, damaging any electrical devices connected to the power grid. Computers would be fried. Automobiles and trucks using electronic ignition systems would be disabled, as would hospital-monitoring devices (e.g., vital-sign monitoring devices, ventilators). Cities would be without public utilities—electricity, natural gas, water and sewage systems—and public transportation. Airplanes would not fly, and defense systems would be disabled. Long-term loss of electrical power would destroy civilization as we know it, reducing the affected area to a preindustrial society.
This type of attack would quickly and severely disable the country and cause widespread deaths due to infrastructure damage. A number of nations adversarial to the United States now have or shortly will have the capability of carrying out such an attack. Russia and China have had this capability for years. More recent additions to this list include North Korea, Iran, and Pakistan. Using a missile and one nuclear bomb, a rogue nuclear state could send a large part of the United States back to the preindustrial era without electricity. Several strategically placed attacks could disable the entire country.
Source Region EMP (SREMP). SREMPs occur when a nuclear device is detonated at lower levels in the atmosphere or near the ground. The effects are considerably more limited compared to a HEMP-class explosion but still may have a range of damage seventy miles or more from the blast. Such an effect could result from the detonation of a suitcase-type nuclear device.
System Generated EMP (SGEMP). SGEMPs threaten satellites and space stations. This type of attack occurs with the detonation of a nuclear device above the Earth’s atmosphere. The EMP thus generated damages the electrical components of satellites and renders them useless for critical communications, navigation services, and intelligence functions.
Non-Nuclear EMP (NNEP). NNEPs are created by radio frequency weapons (RFWs). These weapons produce an electrically induced EMP (wideband microwaves) or explosion-induced magnetic fields sufficient to disable electrical components in critical systems or vehicles. These types of weapons have been in use since the 1960s and are available to many nations.
In summary, both naturally occurring and made-made EMPs pose a significant threat to your safety and well-being. Surviving this type of disaster requires an extensive and well-thought-out disaster preparedness program.
