The pulsing power of EMP

July 20, 2008

An electromagnetic pulse, EMP, is created when the radiation of a nuclear blast at high altitudes interacts with the ionized layers of the upper atmosphere and the earth’s magnetic field. If an electromagnetic pulse were fired off in the atmosphere above the United States. not only the power grid, but everything that runs off an electronic circuit board -- which means your phone, your late-model car, your computer and anything that has a chip in it -- might be wrecked.
It would be like the effect on our cheap telephone when it was hit by a static electricity spark: the dialing chip died. If an EMP weapon were set off we’d be thrown back into the 19th century. Maybe a Model T Ford would still run, but not much of anything else.
The fear among scientists is that a terrorist group or a foreign enemy, such as Iran, might create an electromagnetic pulse. Instead of killing people, like the U.S. bombing of Hiroshima, an EMP kills electrons.
Iran has already tested its ability to detonate a warhead at high altitudes where, if it were a nuclear device, the atmospheric reaction could trigger a massive EMP that could cripple the United States for months or even years. That was what William R. Graham, President Reagan’s top science adviser, reported to a congressional committee in 2005. An EMP is the greatest threat to our country.
The reason why the Enola Gay B52 that dropped a nuclear bomb on Hiroshima was not crippled by an EMP pulse was that it flew too low for the effect. Had the bomb exploded high in the atmosphere between 10 and 20 miles up, the blast would trigger a high altitude atmospheric reaction. The range of the EMP effect depends on the altitude of the blast.
A bomb set off at the optimum altitude, 250 to 312 miles over Kansas, would cause a disruption of the entire continent. Everything that uses electricity would be affected. Airplanes would lose their computer-controlled devices such as radar and GPS navigation.
This kind of nuclear attack does not require the smuggling of a device into a port aboard a ship, but can be launched at sea on as primitive a rocket such as a Scud missile. Scuds are plentiful in the arms market and sell for a reported $100,000 apiece, mere chump change. The Scud can reach the desired altitude and though they are not very accurate, for an EMP blast they don’t have to be.
That’s one of the reasons our government is so fearful of the long range missiles being tested by Iran, but any enemy able to obtain such a weapon and a suitable launch rocket for high altitude detonation represents a threat. Launched from a ship at sea, such an attack could shut down the entire East coast.
An EMP lasts only about one second, but that’s enough. Almost no device running off electricity would work. The pulse would be like the power surge that can burn out your refrigerator compressor. It all sounds like science fiction, but there have been cases of planes affected by electromagnetic pulses. This is not something that occurs only in a laboratory.
Scientists have warned Congress that lack of imagination is what prevented us from realizing the potential of a 9/11 attack. An EMP attack would be far more devastating.
Years ago I wrote a short story, “The Link,” about the impact on the U.S. economy if the weak link in the power grid could be dismantled. We have already experienced the failure of the power grid that plunged the East coast into darkness (and triggered a spike in births nine months later) but I never imagined something as devastating as an electromagnetic pulse. You might have suffered an extended power outage because of an ice storm and had to live for a few days without lights, a stove, a TV, and a deep freeze. Imagine the impact of a month or year long nationwide disruption. An EMP would shut down everything. We have been warned.

“The Link” is one of the short stories by Harley Sachs in the collection “Misplaced Persons” available from the online printer www.lulu.com and from Wings ePress. Visit the web site
www.hu.mtu.edu/~hlsachs where you can listen to two stories, read a third,
read reviews, and find links to the publishers of my books.