In today’s world we have come to depend upon all of our electronic toys. Without them society would be in chaos, the power grid will collapse, most vehicles will stop, and computers will not function. Most people today have no idea of what the effects of a high-altitude electromagnetic pulse (HEMP) device would be.
An electromagnetic pulse (sometimes abbreviated EMP) is a burst of electromagnetic radiation that results from an explosion (usually from the detonation of a nuclear weapon) and/or a solar flare. The resulting rapidly changing electric fields or magnetic fields may couple with electrical/electronic systems to produce damaging current and voltage surges.
In military terminology, a nuclear bomb 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.
The following map show the effect of a 1-2 megaton weapon detonated at different altitudes about the United States.
The following is the statement of Senator Jon Kyl after hearing witnesses on the effects of a HEMP attack on the United States
STATEMENT OF SENATOR JON KYL, CHAIRMAN
SUBCOMMITTEE ON TERRORISM, TECHNOLOGY, AND HOMELAND
SENATE JUDICIARY COMMITTEE
“TERRORISM AND THE EMP THREAT TO HOMELAND SECURITY@
8 MARCH 2005
Last year, the EMP Commission found that EMP was one of a small
number of threats that could hold our society at risk of catastrophic
consequences. The effects of an EMP could potentially shock, damage, or
even destroy electrical systems that fall within the striking range of a nuclear
detonation. And because the United States is heavily dependent on electrical
systems to provide basic services, an EMP attack has the potential to have a
cascading effect on all aspects of American society
The Commission’s report found that our infrastructure – such as
electrical power, telecommunications, energy, financial, transportation,
emergency services, water purification and delivery, and food refrigeration –
were all vulnerable to EMP attack. And in the event of an EMP attack, those
infrastructures would be rendered unusable, thus inflicting widespread
disruption or failure on a national scale. The death toll from such an attack
is almost unthinkable. Unfortunately, the House Armed Services Committee
hearing on the Commission Report occurred on the date of the release of the
9/11 Commission Report. As a result, the hearing – and the EMP Report –
received virtually no coverage.
There are some things that you can do to protect yourself and your electronics from EMP.
One is the use of a Faraday cage. In the next few days we will post a simple design to help you protect small items.