Alcatel, one of the major submarine cable builder in the world, has an interesting resource page on submarine cables like an animation on how to repair submarine cables cut. (via Ben Frankes)

The animation looks easy. Detect the cut, pick up one cable, then the other and then join them back. Even considering it takes time to find the cables, it normally dont take more than 48 hours to fixed the cut.

So what did it takes so long to fixed the cable at the recent cable cut with some estimates going up to nearly 3 weeks?

Well, in an earthquake, the cables are displaced from its original expected position. Not only the cables are displaced, earthquake also causes landslides, which means the cables may be potentially buried. In a massive earthquake, there could also be multiple cuts. Displaced, hidden with multiple cuts, locating the sever submarine cables is like finding needle in the haystack.