The older wire based are more at risk, fiber is immune. I am not sure of the housing or any internal steel wires used for strength, but fiberglass or kevlar strength cable are also immune. Armor?- steel - that would get a current hit but would attenuate it via the spiral current path. In addition the conductive volumetric shield of deep sea water would also attenuate the EMP?
Do modern fibers need repeaters? or do they use distributed amplification via co-carried laser light that offsets losses?
Long haul fibres need EDFAs to boost the optical signal so that it can travel through thousands of kilometers of fibre. EDFAs need laser light to perform amplification. Generating laser light requires electricity. Electricity requires conductive wires. Conductive wires are susceptible to induced currents caused by solar flares over large distances.
The IEEE brings this up every few years into relation with the electrical grid. A massive solar flare will likely result in humanity being thrown into chaos for multiple years with large chunks of infrastructure being offline until low volume high cost replacement parts (especially high voltage transformers) are built.
That's because your submission points to the copy of the Wired article now hosted by arstechnica... the question though remains when you ask why there are two threads for that same Wired article, on the same day.
There’s an event like this on average every sixty years.
So far we’ve been lucky, and haven’t gotten any hits since we started covering the planet in sensitive electronics. The chance of that happening next year is about 1/60. YMMV on whether that is high or not.
