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EMP-Shielded Power Grids Under Development
An anonymous reader writes with this excerpt from MarketWatch:
"A one-megaton nuclear bomb detonated 250 miles over Kansas could cripple many modern electronic devices and systems in the continental US and take out the power grid for a long time. ... A solar storm similar to the one that occurred in 1859, which shorted out telegraph wires in the United States and Europe, could wreak havoc on electrical systems. Each of the above scenarios can create a powerful electromagnetic pulse that overloads electronic devices and systems.
IAN staff and Frostburg State University physics and engineering professor Hilkat Soysal are teaming — through a $165,000 project recently approved by the Maryland Industrial Partnerships (MIPS) program — to create renewable energy-powered, electromagnetic pulse (EMP)-protected microgrids that could provide electricity for critical infrastructure facilities in the event of a disaster."
Also available are an EMP threat assessment (PDF) written for the US Congress and an estimate of economic impact (PDF).
Not unless they are very very deep. Cables are usually more conductive than the ground. The EMP will continue deep into the ground, and will be picked up by cables like a several miles long antenna.
Solar flares cause problems because they induce an extermely low frequency charge on a transmission line. This low frequency is practically a DC voltage which can saturate the core of transformer thus causing a blackout. Coupling the line through a large capacitor bank filters out this DC component thus negating much of the effects of a solar flare.
You kind of have it backwards. You want to put the cables in a conductive conduit. The air layer would be non-conductive already, though there are simpler ways to achieve that (e.g., rubber or plastic).
What do they teach kids in schools these days. Let me explain. The scenario is the detonation of a 1 megaton nuclear device at 250 miles. That's in space, btw. It would not directly kill a single person. When that happens the EMP field would actually cover the US and a good chunk of Canada, and parts of Mexico. Wait, he's gonna say that I'm full of crap.... proof: http://en.wikipedia.org/wiki/High_altitude_nuclear_explosion Look at the effects while you're there. And if you say that it can't happen.... You'll see that it already has been done.
From the Wikipedia page on EMP (which quotes a Federation of American Scientists article):
"The pulse can easily span continent-sized areas, and this radiation can affect systems on land, sea, and air. The first recorded EMP incident accompanied a high-altitude nuclear test over the South Pacific and resulted in power system failures as far away as Hawaii. A large device detonated at 400â"500 km (250 to 312 miles) over Kansas would affect all of the continental U.S. The signal from such an event extends to the visual horizon as seen from the burst point."
The test mentioned is the Starfish 1.4 megaton high altitude test. That link has many more details.
EMP affects all sorts of electrical devices. Car computers would likely be more seriously affected than vintage, non-computer cars unless they have been EMP shielded as most military equipment is. Most regular cars have no such protection.
There are many other ways to form EMPs. The problem is making them powerful enough. A shorted out magnetotron in a microwave generates enough EM to screw up any nearby electronics (blew out my microwave, killed my computer, TV, router, and stereo. Everything else in other rooms were fine, just the kitchen and living room were affected, and they're on separate circuits.)
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
EMP threat is way exaggerated
http://www.alternet.org/story/25738/
A 1.4 megaton thermonuclear weapon detonated 250 miles above Johnston Island in the Pacific affected street lamps, circuit breakers, cars and radio stations in Hawaiian, 800 miles to the north. Starfish Prime was a thermonuclear device with a yield over a hundred times that of the bomb dropped on Hiroshima. Minimal damage 800 miles away. 1% of street lights and some fused ignitions in cars.