An Electromagnetic Pulse (EMP) works by overwhelming electric circuits with an intense electromagnetic field. A non-nuclear EMP explodes a metal cylinder full of explosives inside a coil of wire, pushing out magnetic and electric fields that fry electric circuits.
A nuclear EMP would explode a nuclear bomb in the atmosphere. The resultant gamma radiation would take in positive air molecules but push out negative electrons, sending a large electromagnetic field in all directions. A lo-megaton device detonated 200 miles (320km) above the centre of the United States would destroy every electronic device in the country but leave structures and life intact.
Solar blackout 2013?
In 1859, a great geomagnetic storm wiped out transmission cables and set fire to telegraph offices when the Sun went through a period of intense solar activity. Scientists at NASA have warned that a similar storm could occur in 2013. The Sun’s magnetic cycle peaks every 22years, while every 11 years the number of sunspots and solar flares hits a maximum. If we were to experience a geomagnetic superstorm on the same scale as that in 1859, our many electronic devices would be damaged. Networks would go offline, aircraft couldn’t fly, satellites would be destroyed.
1.12 Tesla – The world’s most powerful MRI scanner at Oregon Health and Science University helps to provide unprecedented insight into the human brain.
2.45 Tesla hybrid – 8 trillion times stronger than a fridge magnet, this electromagnet at Florida State Uni has the strongest continuous magnetic field.
3.100 Tesla – At a laboratory in Sarov, Russia in 1998, explosives helped to create a 3,100 Tesla magnetic field, instantly destroying the machine.