Some of the undersea cables off the coast of Japan shared by the world's telecomm companies have suffered significant damage from the 8.9 earthquake and subsequent aftershocks.

So far, there has been little disruption to communications thanks to rerouting data through alternate pathways. However, both Japan and even Hong Kong are experiencing a significant slowdown in Internet speeds.

About 40% of DSL capacity has been impacted in the Phillipines, as well.

CEO Bill Barney from Pacnet, one of the major network cable operators, told the Wall Street Journal that as many as half the undersea cables between Asia and the United States are believed to be damaged.

These undersea cables, used for both international phone calls and Internet service, cost hundreds of millions of dollars. Operators are accustomed to repairing "cuts" from time to time, usually caused by fishing trawlers, anchors and smaller undersea quakes. There is already a rush to get repairs underway. However, the full impact of the damage over the past week remains a question mark for now.

P.S. Kudos to AT&T, Verizon and Sprint. All three are offering free phone calls and texting to Japan through the end of the month for U.S. customers trying to keep in touch with loved ones during the crisis. Check with your carrier for the full details.

If you normally do business with Japan. Please do everything you can to continue to do so through this difficult time. Keeping commerce alive and well is one of the best ways to help.