news on sina.com.cn, in which China Telecom, one the biggest ISP in China, release an official statement( with my rough translation)This really throws the notion of "cyberspace" into the physical world. My sympathies to everyone affected. Hope they figure out how to fix those cables quickly.
China Telecom has confirmed that, according to China institute of earthquake monitoring, at Dec 26, 20:26-20:34 Beijing Time, 7.2 and 6.7 magnitude earth quake have occurred in the South China Sea. Affected by the earthquake, Sina-US cable, Asia-Pacific Cable 1, Asia-Pacific Cable 2, FLAG Cable, Asia-Euro Cable and FNAL cable was broken and cut up. The break-off point is located 15 km south to Taiwan, which severely affected the International and national tele-communication in neighboring regions.
It was also reported that communication directed to China mainland, Taiwan, US and Europe were all massively interrupted. Internet connection to countries and region outside of China mainland became very difficult. Voice communication and telephone services were also affected.
China Telecom has claimed that due to the aftershock of the earthquake, the repairing works would be very tough. In addition undersea operation is also not easy to handle with. So this phenomenon is going to exist for certain period.