End-of-the-world novel? A video game? Or could such a scenario loom in America's future?
Electromagnetic pulses (EMP) are oversized outbursts of atmospheric electricity. Whether powered by geomagnetic storms or by nuclear blasts, their resultant intense magnetic fields can induce ground currents strong enough to burn out power lines and electrical equipment across state lines.
The threat has even become political fodder, drawing warnings from former House speaker Newt Gingrich, a likely presidential contender.
"We are not today hardened against this," he told a Heritage Foundation audience last year. "It is an enormous catastrophic threat."
Meanwhile, in Congress, a "Grid Act" bill aimed at the threat awaits Senate action, having passed in the House of Representatives.
Fear is evident. With the sun's 11-year solar cycle ramping up for its stormy maximum in 2012, and nuclear concerns swirling about Iran and North Korea, a drumbeat of reports and blue-ribbon panels center on electromagnetic pulse scenarios.
"We're taking this seriously," says Ed Legge of the Edison Electric Institute in Washington, which represents utilities. He points to a North American Electric Reliability Corp. (NERC) report in June, conducted with the Energy Department, that found pulse threats to the grid "may be much greater than anticipated."
There are "some important reasons for concern," says physicist Yousaf Butt of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass...
Simple physics, big worry
The electromagnetic pulse threat is a function of simple physics: Electromagnetic pulses and geomagnetic storms can alter Earth's magnetic field. Changing magnetic fields in the atmosphere, in turn, can trigger surging currents in power lines.
"It is a well-understood phenomenon," says Butt, who this year reviewed geomagnetic and nuke blast worries in The Space Review.
• On March 9, 1989, the sun spat a million-mile-wide blast of high-temperature charged solar gas straight at the Earth. The "coronal mass ejection" struck the planet three days later, triggering a geomagnetic storm that made the northern lights visible in Texas. The storm also induced currents in Quebec's power grid that knocked out power for 6 million people in Canada and the USA for at least nine hours.
Super solar storm
On the solar front, the big fear is a solar super storm, a large, fast, coronal mass ejection with a magnetic field that lines up with an orientation perfectly opposite the Earth's own magnetic field, says solar physicist Bruce Tsurutani of NASA's Jet Propulsion Laboratory in Pasadena, Calif
"It has to be the perfect storm," Tsuratani says.
"We are almost guaranteed a very large solar storm at some point... Three power grids gird the continental U.S. — one crossing 39 Eastern states, one for 11 Western states and one for Texas.
"A lot of the questions are what steps does it make sense to take," Legge says.
"We could effectively gold-plate every component in the system, but the cost would mean that people can't afford the rates that would result to pay for it."
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