EMP: How It Blasts Electronics -- Even Unplugged

An Electromagnetic Pulse (EMP) is a burst of energy that destroys electronics. Terrorists can create the frying pulse of energy using several methods, but the damage inside electronics happens the same way.

EMP energy floods the wires and circuits in electronic devices -- the more wire and circuit, the more energy captured. Generally, EMP effects electronics that have any of the following:

  • Circuits larger than a wrist watch;
  • An antenna;
  • A connected power cord, especially if that cord is plugged in to a wall outlet.

In less than a second, the EMP blasts up to 50,000 volts of energy at your electronics. Most modern business and consumer electronics have limited shielding and cannot survive this strong burst.

The pulse melts the circuit's tiny metal pathways. Modern computer CPUs, the "brains" of electronics, are especially vulnerable. That is because faster CPUs require smaller internal pathways. The smaller connections are more fragile and closer together, making them melt more quickly. The logic switches inside the CPU are also easily damaged by energy spikes.

The energy burst can even destroy unplugged electronics. That is because the EMP energy travels like radio waves, slamming into any electronics large enough to act as an antenna.

The amount of damage depends on they type of attack and where you are in the energy-burst pattern.

Communication will be one of the biggest problems after an EMP attack.

  • Cell phone towers will slowly reset or be repaired, but your cell phones may be destroyed.
  • Regular phone lines will be either be dead or will be overloaded with calls.
  • Internet connections will be damaged or destroyed and may be the slowest to recover.
  • Unprotected radios may be damaged or destroyed.
  • Power may be out for hours to months, depending on where you live.

How will you communicate with your business and family? Read our pages: What to Protect and How to Protect.

"Widespread functional collapse of the electric power system
in the area affected by EMP is likely."

US EMP Commission's Report to Congress, Volume 1: Executive Report