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Comment by mikeocool | Hacker News Reader

Yeah, I was thinking the same thing, almost all the transatlantic cables seemed to have been laid in the 2000s as well. I ran across this: http://en.wikipedia.org/wiki/Transatlantic_telecommunication...

Seems like each cable generally only has a life of 10-20 years.

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Hmm, then what happens to outdated cables? Do we pull them up, or do we just turn off a switch at the shore and leave the rest in the ocean? Do the cables contain any substance that might pollute the seabed as the casing degrades away?

Probably, but we dump orders of magnitude more crap (both in volume and in hazard) in the ocean every day.

Plus, the impact from burning the fuel it would take to have a ship pull up a cable would be thousands of times worse than anything the cable might do.

I'm sure they're left in place.

I can't imagine what materials they would be made of that would be particularly harmful. My sense is they're mostly constructed of things like rubber, plastics, other polymers, steel, copper, and of course a little glass fiber.

Given the high price of copper I would guess that they pull the copper cables out after service. I am not so sure about fiber cables.

Given the cost of such an operation, I don't think you can get some profit even if they were made of gold.

As time passes, most of the cable is buried deeper and deeper under debris that falls on the ocean floor. This means that you cannot just pull it up, you would have to dig to get it out.

Most cables don't run on the seabed.

Umm, then where do they run? They can't float in the middle of the water.

Uh, yeah they do. Often they hang from a buoy, floating in the middle of the water.

Go a few miles out and there is very little to debris to fall onto the ocean floor.

In certain cases, e.g., the cables AT&T laid between Hawaii and the mainland US, they were decommissioned from active service and then used to power a network of undersea sensors used for research by the University of Hawaii:

http://aco-ssds.soest.hawaii.edu/

The APNG-2 cable (http://en.wikipedia.org/wiki/APNG-2_(cable_system) ) reused part of the PacRimWest cable. They literally pulled some of it up, respliced it and moved the end-point to Papua New Guinea.

10-20 years...gez there must be a lot of cables down there then. I am sure that some kind of salvage operation would be worthwhile if well thought out...it wouldnt be easy to do it at a profit but i could sure go for a few thousand kg of copper!

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