Italian technicians manipulate a high-tension under-sea cable.
Italian technicians manipulate a high-tension under-sea cable. - 
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Jeremy Hobson: Well in the horrifying videos and images of the tsunami that hit Japan, there's one thing you can't see. But damage to it would affect us right here in the U.S. I'm talking about the long phone and Internet cables that run under the Pacific Ocean.

Marketplace's Eve Troeh reports on how telecom connections are faring.

Eve Troeh: You may think of your cell phone or your Internet service as "wireless," but it's really not, says Eric Bender. He runs WilCon, a hub in downtown Los Angeles where millions of phone calls, videos and other digital data packets make one last stop before they get to customers. If they come from overseas, he says, there's lots of wire involved.

Eric Bender: This is a map of the submarine cables of the world.

Troeh: 2011 edition.

Bender: Yeah, this is the new one I just got.

Thousands of miles of whisper thin fiberoptics are wrapped tight in plastic and metal, and laid under the ocean floor. They can be as slim as your finger, or a few inches thick. They run between beaches in Japan and California.

Bender: They come in from under the sea, under the sand, and then on the shore there's a building, you wouldn't even know, just a block building, and then they're run throughout the U.S.

In Asia, Japan is the telecom point of entry. Six cables connect it to the U.S. At least two of those were damaged last week. And more lines within Asia got hurt. Each new underseas connection costs up to a billion dollars, so the telecom giants pool their money to buy them, and, says Eric Bender, pitch in when things go wrong.

Bender: At times like this, all the carriers internationally tend to work very closely together because it may not be them this time, but the next one could affect them.

Companies like his help reroute data when disaster strikes. Tim Strong at Telegreography Research says Google, Verizon and other big companies are ready when cables snap.

Tim Strong: These kind of breaks happen all the time.

Ship anchors, fishing nets, or just the ocean floor shifting cause undersea cables to break up to 100 times a year. Companies can detect the breaks virtually, when their data bounce back. But they can't fix things from afar.

Strong: For that you need old-fashioned ships to go out with people to splice the cable again.

And he says crews are headed to do that off the coast of Japan right now. Think of them next time you're reading online news about the quake.

In Los Angeles, I'm Eve Troeh for Marketplace.

Follow Eve Troeh at @evetroeh