What if the 1859 Carrington Event happened again tomorrow?
February 6, 2013 9:31 AM   Subscribe

The 1859 Carrington Event triggered the largest Geomagnetic Storm in recorded history, crippling the relatively small-scale telecommunications systems of the day and causing widespread electro-magnetic disruptions around the globe. If another EM event on that scale occurred today, what would be the likeliest impacts to our telecommunications systems, electrical grids, and magnetic storage media?

I'm not looking for doom-mongering or speculative philosophizing/moralizing about the dangers of technological dependence or the bigger-picture economic and social fallout, etc., what I'm looking for are realistic, technical assessments of the likely immediate, practical effects in the context of modern technological infrastructure. Would powerlines burst into flames, or probably not because they're too well-insulated? Would magnetic media be left unreadable? Etc.

A few highlights from what happened in 1859, to give a sense for the scale and magnitude of the event:
  • "...telegraph communications around the world began to fail; there were reports of sparks showering from telegraph machines, shocking operators and setting papers ablaze.
  • "...a telegraph manager in Pittsburgh, reported that the resulting currents flowing through the wires were so powerful that platinum contacts were in danger of melting and “streams of fire” were pouring forth from the circuits."
  • "...telegraph operator Frederick W. Royce was severely shocked as his forehead grazed a ground wire. According to a witness, an arc of fire jumped from Royce’s head to the telegraphic equipment."
  • "When American Telegraph Company employees arrived at their Boston office at 8 a.m., they discovered it was impossible to transmit or receive dispatches. The atmosphere was so charged, however, that operators made an incredible discovery: They could unplug their batteries and still transmit messages to Portland, Maine, at 30- to 90-second intervals using only the auroral current."
posted by saulgoodman to Technology (5 answers total) 22 users marked this as a favorite
One thing that would happen (assuming the existing safeguards aren't enough to stop this) is that the transformers at either end of very long (north/south, I think) transmission lines will be stressed and damaged. Geomagnetically induced currents end up creating a *DC* voltage differential in "ground" across the length of the transmission lines, and (if unchecked) this will drive the transformer beyond its normal operating limits by creating an offset with the AC voltage.

There was a big (not as big as the Carrington Event) event in 1989 that hosed the power grid, particularly up in Canada.
posted by rmd1023 at 9:53 AM on February 6, 2013 [1 favorite]

Astrophysicist who studies stellar flares and their effects on planets here. There is actually a whole study on severe "space weather" (a.k.a. solar storms) that you can read for free online, or download as a PDF.

The upshot is that a Carrington Event-like solar storm would be very bad news for our technological infrastructure. The US power grid is highly interdependent, and it's not aging gracefully. In addition, satellites are particularly vulnerable to the effects of space weather, including not only direct damage, but by orbital changes caused by drag from Earth's atmosphere (which becomes heated and puffs up a bit when hit by large storms-- this is in fact how most space junk gets cleaned out of orbit).

You might enjoy (or be kept up at night) by the table on page 40 (show classification of kinds of storms and potential impacts) and Figure 7.1 on page 78 (which shows sections of the grid potentially impacted by a large storm-- spoiler alert: it's almost all of it!).

The good news is that our Sun is not a very magnetically active star-- it's quite calm most of the time, relative to some of the other kinds of stars that are out there (and relative to its past-- stars have more of these kinds of events when they are young, and our Sun is middle-aged). The bad news is that observations of stars that are like our Sun by the Kepler mission seem to show that while big solar storms are uncommon, they may still happen every few hundred years or so.
posted by shaka_lulu at 12:04 PM on February 6, 2013 [9 favorites]

Thanks for the great answers so far! Any ideas about how/if magnetic storage media might be effected?
posted by saulgoodman at 12:09 PM on February 6, 2013

On a local level, the effects of a geomagnetic storm are pretty small - the earth's magnetic field will be distorted but still won't be varying more than a percent of it's full strength. What this distortion of the field does is shift the equilibrium where the electrons moving around in the earth's crust get (slightly) concentrated. This causes a fair amount of current through the earth. But if there's a big metal conductor that current can use as a shortcut, a large area's electrons will be funneled through it. That's how terrestrial electronics can be damaged.

But again the local variations in the actual magnetic field are not very string - weaker than the changes you experience from moving in and out of metal structures.

Magnetic media will not be affected.
posted by aubilenon at 4:15 PM on February 6, 2013 [2 favorites]

Royal Academy of Engineering says: UK must plan now to defend itself against extreme solar weather events

"Extreme space weather: impacts on engineered systems and infrastructure" (PDF)

(via the BBC)
posted by KatlaDragon at 11:36 PM on February 6, 2013

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