### After last week’s post on a Carrington storm – a solar event able to do large-scale damage to anything electrical, especially power grids. I fielded a few questions which deserved a post. And I had some new ones of my own…

Does the whole Earth get hit?
The issue isn’t the Coronal Mass Ejection that goes with the flare, but the magnetic storm the CME provokes when it hits us. This affects the whole Earth in one hit, because the Sun-side of Earth’s magnetic field is pushed. The shadow side is pulled and zings back. Here’s an animation:

How powerful are these geomagnetic storms?
It depends on the CME, which – don’t forget – is super-hot plasma. The biggest can mass up to 100,000,000 tonnes, moving at up to 1000 km/second. These can really bang into our magnetic field. The current the geomagnetic storm induces in conductive material on Earth will vary as a result of the speed of the field movement, and of the scale of the conductive material. This acts like an aerial, so the more conductive material, the higher the voltages and current induced in it. That’s why the power grid is vulnerable, because transmission lines act as aerials and transformers have copper windings.

Can the excess voltages be calculated?
The voltage generated in a conductor is a product of the rate of change of magnetic flux and the direction of the field lines relative to the conductive material. In a closed loop like a transformer, for instance, this voltage can be calculated by Faraday’s Law of Induction, via James Clerk Maxwell, which states that the negative of the rate of change is equal to the line integral of the electric field. This is a bit of math that quantifies results when direction and intensity are both changing.

Will a geomagnetic storm burn out all power grids?
It depends on the loading of the grid and on the intensity of the storm, which will differ from place to place because the rate of change and flux direction keep changing. A heavily loaded power grid is more vulnerable because it’s operating closer to its designed tolerances. Needless to say, in this age of engineering to cost, some grids are fully loaded in normal operation. That’s why even the modest geomagnetic storms of in the last few decades have sometimes generated localised blackouts – some grids were vulnerable when others weren’t. With a big enough geomagnetic storm, all power grids would be blown out.

What about domestic appliances – computers, hand-helds and so forth?
It depends on the intensity of the storm. Anything plugged into the mains would suffer a voltage spike. Your stove or kettle wouldn’t notice it. Your computer might lock up. A re-boot might fix it, if the power stayed on. Or gear might be physically damaged. Newer devices are more vulnerable than old, partly because the older stuff was over-engineered. Anything with looped wire in it, like an electric motor – which includes DVD drives – might be at risk. Just about everything relies on low-voltage CPU’s these days, including cars, and it’s possible a really big geomagnetic storm would damage some of these. The effects probably wouldn’t be consistent across all gear because there are so many variables in electrical hardware, including whether it’s operating or not when the storm hits.

So some stuff, like the old Morrie Thou every Kiwi wishes they never got rid of, would still work and we’d otherwise mostly be OK?
Don’t forget, there won’t be any mains power, possibly not for months. No water pumps. No sewerage pumps. No heat. No light. No cooking. No battery charging. Hospitals out of action just when needed. Shall I go on?

Please don’t. Will the storm induce current in anything else?
Gas and oil pipelines. Older plumbing. They’re metal too.

Sounds scary. Is there anything we can do?
NASA has satellites on solar weather watch. They’re also implementing Solar Shield, an early-warning project. Whether anybody pays attention to warnings, or even hears them, is another matter. Even if the warning’s broadcast, who listens to dumb science stuff when the rugby news is about to start? But if you hear a warning, turn everything off, keep things unplugged, get your emergency kit stocked with food and water, buy a can opener, dig a long drop, and so on.

Is there a plus side?
We’d get amazing aurora displays towards the equator. Would that compensate for the damage? Uh…no.

## 6 thoughts on “Beware the next Carrington storm – a Q&A wrap-up”

1. bevrobitai says:

Tee-hee – we’re all doomed…DOOMED! But there are other advantages beside the aurora – no more constant TV news of world disasters, famines, shootings and all the other awful things beamed into our living rooms, so we’ll only have to worry about our own immediate lives. No more pre-packaged unhealthy food – we’ll be on a simple and restricted diet so should feel healthier, and we’ll be getting LOTS more exercise! Our entertainment will be each other, face to face, playing parlour games like the Victorians did. We will sing again, and play musical instruments ourselves instead of passively listening to others. We’ll spend more time with our families and work together to survive – everyone will have a purpose and a job to do. There will be an upsurge of creativity and innovation as clever minds find ways to use our resources to improve our circumstances.
After spending two years thinking and writing about life after a Carrington event I’m actually quite optimistic.
I’d miss your blog though, Matthew. 😉

1. Writers always find ways of communicating. My backup is semaphore signals and beacons on hilltops 🙂 Yes, without power the western world’d have to drop back a couple of centuries & re-learn what interactions within our small community groups was all about. I suppose here in NZ the old ‘Social’ would be resurrected, complete with people bringing ‘plates’.

2. Read your post last night just before I logged off and was thinking, “it’s always something” a la Rosanne Rosanna Danna (Saturday Night Live), mostly meaning that life really does turn on a dime or being completely present in each moment really does make sense. Upon awakening this morning, I found myself thinking along the lines of bevrobitae (thank you for pointing me to her books), although I would miss blogging and reading my favorite blogs (of course, yours is one) but if it’s a matter for the greater good….However, I think I will start hoarding writing materials and supplies for my cat. Two centuries ago, ships did sail so perhaps I could send a letter to scientist Matthew the historian in New Zealand as there are no real hilltops in Florida unless you include the bank of a swamp, and then there are all those trees….

Really enjoyed these two posts, Matthew!
Karen

1. Yes, we never know quite what’s up next; but worrying about the unknown future serves only to destroy the moment now – and that moment, now, is all we really have. It is to be savoured. That doesn’t mean being unprepared, of course. It’s a philosophy that occurs to me, quite often, as I walk through central Wellington – a place vulnerable to major earthquake and yet where the glass-walled high-rises with their vulnerable cladding soar on every side and the trolley bus cables obstruct escape into the street (they’re removing the wires for this reason by 2017). I watched a panel fall from one of those buildings a couple of years ago, mercifully missing a woman walking by with a pram. For me the potential (no pun intended) of a disastrous geomagnetic storm underscores another fragility of our civilisation – a civilisation that to me often seems a house of cards. You’re right – 200 years ago, people DID carry on vigorous correspondence, by letter-and-sailing ship. Not the immediacy of today, but that didn’t reduce the discussions that went on.

3. bevrobitai says:

One more question for our resident science guru – if and when the earth’s magnetic polarity reverses as it has in the past, is that like dropping our shields for however long it takes?

1. The jury’s largely out on that one. The evidence is that the dynamo effect of the Earth’s core leads to polar flipping and instabilities, but the pattern has been hard to pin down. It can be very quick, or can take up to 10,000 years for the pole to reverse, during which time Earth can end up with a chaotic field that embodies several magnetic south or north poles. Magnetic field strength drops, but maybe not enough to eliminate the Van Allen belts and affect Earth’s fragile biosphere – the arguments continue over whether any of the ‘great extinctions’ can be linked to polar flipping. The most recent such event was just 41,000 years ago. It’s subject of ongoing study…So I guess the best answer is ‘nobody quite knows’, and ‘watch this space’. From the viewpoint of magnetically induced electrical currents, the rate of change – even at its fastest – is too slow to provoke damaging voltages of the Carrington Storm variety; the issue is the way the Van Allen belts will disappear and so allow more radiation flux than usual to hit the Earth.