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This was a good read. I'm obsessed with undersea cables. I consider them one of the wonders of the modern world. Wikipedia says 99% of all internet traffic gets delivered via these ocean-spanning wires, just sitting along the sea floor. Almost unbelievable.
I can't believe this article does not mention what I think is the most puzzling part of the repair: the delicate process by which the individual fibers are FUSED TOGETHER in a way that maintains near perfect total internal refraction.
Do they maintain the original connection between the fibers or is that not worth the effort and is a swap not a problem?
I thought I had read that some cables have systems at each end to detect and correct when there's a splice with swapped cores, however, I can't find a reference; you could imagine such a system would mitigate partial breaks by assigning working paths to priority customers. However, I see a lot more about automatically aligning multicore fibers for splicing, I suspect proper alignment may be more practical than fixing it at the ends.

Even if it's not automated, the number of cores in multicore fibers tends to be pretty low, and there's a standard for marking fibers [1], that's similar-ish to the standard for marking copper pairs [2].

[1] https://en.wikipedia.org/wiki/TIA-598-C

[2] https://en.wikipedia.org/wiki/25-pair_color_code

I've been attempting to buy a cross section of one of these cables for a very long time. Anybody got a lead on one?
If you sink a few old ships around in the area you will never need to repair it again each two years. Extra bonus if they are exactly the same ships that you found red-handed damaging the cables.
tl;dr: They pull the damaged cable up, weld it to a new section of cable their brought, and then drop the cable with a detour to make room for the extra length.

(This is a really meandering article!)

"Repeaters are included every 40-80 km to keep the signal strong."

Does it mean that there's a ton of repeaters under the sea? Where do they get the power from?

They are like bulbs on an old-school Christmas tree light string, all in series with just one insulated conductor between.
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> Cables can be tapped for information, or cut to drastically slow communication between countries. A greater emphasis on government protection of the cables may be in the future.

That left me wondering now, how would that even work? The wiretapping, that is

Is it possible to tap into these cables for espionage purposes?
"In 1858, when the first submarine cable was installed, sending a message across the Atlantic took nearly 18 hours."

If anyone is curious as to why it took so long: https://en.wikipedia.org/wiki/Transatlantic_telegraph_cable

TLDR: "smearing" of the signal (capacitance), no underwater amplifiers, very faint signal at the end.

I've read a number of articles on this topic, but there's one issue I've never seen addressed: With the large number of cables now in place, often with multiple cables running along similar paths, how great is the risk that in the course of raising up one end of a broken cable, you accidentally snag some other cable that was laid across the first cable after it was laid? Or is the ocean just so vastly, hugely, mind-bogglingly big that hardly any cables cross over each other?