This doesn’t affect you directly but it’s an interesting glimpse at How Things Work.

The vast bulk of international voice and Internet traffic travels through underwater cables. There were several reports in 2008 of broken or cut cables in the Mediterranean, giving rise to conspiracy theories and talk of terrorists, and making us wonder a bit about whether the Internet is really as invulnerable as we were led to think. In January, two cables were cut in the Mediterranean, causing Internet disruptions and slowdowns for users in the Middle East and India. On December 19, three more cables were cut, disrupting 75% of communication between the Middle East and Asia and the rest of the world.

This article in New Scientist describes why the Mediterranean is “the Achilles’ heel of the web,” relying on three main cables to link Europe, North Africa, and Asia. There are other ways to route traffic when those cables are unavailable but slowdowns and outages are still possible. More cables are being laid at a fast pace so this problem will be alleviated over time. It’s not really an issue in the Atlantic, for reasons that are pretty obvious when you look at the chart below.

undersea cable map

There are other areas that rely on fewer cables than you might suspect to stay in touch with the rest of the world. The causes of the breaks in 2008 are not known with certainty but the New Scientist article notes that breaks are not uncommon and are most likely caused by undersea earthquakes. Or as one post on Slashdot put it, “Perhaps designing something that is several thousand miles long, and under several hundred PSI of pressure, to lay at the bottom of an environment that contains sulphuric acid plumbs, volcanic pits, and large numbers of angry monsters, is not easy.”

The cover story about earthquakes is comforting but it sounds like a cover-up to me. People would panic if they heard the truth about the giant terrorist squid, right?