[katieHaylor (OP)]

Charlie wants to know:

What would happen to the world if a massive solar flare impacted the earth today, on the scale of the "Carrington Event"?

What do you think?

[alancalverd]

I've just finished watching the box set of "COBRA", a neat bit of political fiction that deals with just such an event. There is no doubt that a lot of infrastructure that we take for granted is actually dependent on a very fragile data system.

40 years ago I attended a seminar on hardening military equipment against nuclear electromagnetic pulse. The specification was relatively simple: a tank crew could expect to live for about 20 minutes after a tactical nuclear exchange, so how can we ensure that the tank continues to function predictably? The best approach was to assume that all semiconductor devices would turn "on", so critical electrical functions have to be protected by overcurrent circuit breakers and replicated by mechanical switchgear. In effect, machines had to incorporate pre-electronic technology. Much was made of a Russian fighter-bomber that was flown to the west by a defecting pilot. It was full of 1950s valve electronics: heavy, inefficient, but capable of surviving an EMP to maintain radio communications and basic radar and navigational function. 

So I would assume that anything which incorporates semiconductors and has not been specifically designed for nuclear combat, will cease to function in a Carrington event. This includes almost every civilian vehicle built in the last 20 years. We have enough experience of grid disruption by small flares to expect that there will be no public electricity supply for months or years after a big one.

[Bored chemist]

"What would happen to the world if a massive solar flare impacted the earth today, on the scale of the "Carrington Event"?"

I might actually get to see the Northern Lights.

It's possible that a mobile phone in the glove box of a car (and thus protected by two (badly built) Faraday cages) would still work...
However, it would only work as a torch and a camera. The transmitter masts would all be scrap metal. There would be no signal
(and you would need a "wind up" charger)

Life on board a nuclear submarine  (assuming it was at depth when the event hit) would carry on as normal- though they might interpret the lack of any sort of command signals as WW!!! and nuke Washington or Moscow as appropriate.

Boris would claim that it would all be sorted out by Easter. However, since his only means to convey that lie would be for him to stand in the street and shout, fewer people would be lied to.
I guess that's an up-side.

On the other hand, plants would still grow. Sheep and cattle would continue to make more sheep and cattle.
Some of us would survive and it would be less of a disaster than a nuclear winter.

On a scale of 1 to 10 I'd say it was a pretty solid 9 but things could be worse.


Somewhere in the world, there will be an island which uses wave power and , because it's in a hurricane zone, buries its power cables , rather than stringing them on overhead lines.
If they had reasonable stocks of diesel, they would suddenly jump to being the world's richest country on a GDP per capita basis.
Enough bits of the internet- designed to survive a nuclear war- might survive well enough for someone to update the relevant WIKI page.

[evan_au]

nuclear electromagnetic pulse

The main difference between NEMP & a solar Coronal Mass Ejection is the frequencies that do the damage:
- NEMP: Frequencies up to GigaHertz, lasting nanoseconds
- CME: Frequencies < 1Hz, lasting hours or a day

The most severe part of NEMP for electronics is caused by a very fast gamma-ray induced voltage step, with frequencies into the Gigahertz range, but lasting only nanoseconds (called E1).
- The wavelength is short, so it can get into very small openings in a case (eg a mobile phone case)
- Even short wires can act as an antenna, and carry voltages into the device which are big enough to be lethal to electronic devices
See: https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse#Characteristics

The longer-lasting part of NEMP (called E3) has lower frequencies, and lasts a couple of minutes. It has some similarities to a solar storm.
- The wavelength is long, so it can't directly enter openings in a case (eg a mobile phone)
- It takes a fairly long wire to pick up a large voltage that might damage electronics (longer than headphones...)

Both E3 and CME do most of the damage by pushing around the Earth's magnetic field, which induces high voltages of < 1Hz over long distances. Any metallic connection between these points will carry very high currents - this includes oil pipelines, electric transmission lines and copper telecommunication lines.
- A Finnish oil pipeline recorded currents of up to 30 Amps (similar to a household 3-phase power supply). The main risk is corrosion.
- Long-distance power lines are susceptible,  if both ends are Earthed. However, most 3-phase transmission lines have one end Earthed, and the other end not Earthed (a Delta-Star arrangement), which provides some protection. However, very low frequencies can be induced directly into the wires, which can drive transformers into saturation, causing them to be shut down and/or damaged, and causing widespread blackouts.
- Fortunately, since the Carrington Event, most nation-wide telecommunications has replaced (Earthed) Morse Code telegraph by optical fiber (not electrically conductive) or by wireless (also not conductive). But they can still be disabled by power failures, if the failure period exceeds the battery backup lifetime.
- A lot of local telecommunications and broadband still passes via copper wires (up to several kilometers), so this could be subject to overvoltages.
- A lot of international telecommunications passes via undersea cables, which uses conductive wires to power repeaters, so these are susceptible. The backup path is via satellite, and satellites are susceptible to high radiation bursts in disturbed radiation belts around the Earth.
See: https://en.wikipedia.org/wiki/Geomagnetically_induced_current