The Hengchun earthquakes occurred between 20.26 and 20.34 on 26th December 2006 off the southwest coast of Taiwan. The 2 earthquakes were measured at 7.0 and 6.9 on the moment magnitude scale. Despite causing only limited casualties and building damage, more far reaching was the that several submarine communications cables were cut, which subsequently disrupted telecommunication services in various parts of Asia.
The earthquake has catastrophic effects on Internet services in Asia, affecting many Asian countries. Financial transactions, mostly in the foreign exchange market were seriously affected as well, all of this happened because of disruption to various submarine communications cables.
A statement from Chunghwa Telecom explained that an undersea cable near the southern coast was damaged, disrupting communications of the country with China, Malaysia, Singapore, Thailand and the United States. The International calling capacity decreased to 40%.
China Telecom states that various international submarine communications cables were broken. IDD, telephone services and internet services of China with North America were seriously damaged by the earthquake. China Telecom announced on December 31st that IDD services had return to normal level. Internet services rose to 70%, resuming its normal level as well. Due to the undersea cables to North America having been seriously damaged by the earthquake, the quality of Internet services depended on the progress of repairing work.
Hong Kong also suffered great effect, from the dawn of December 27th, connection between foreign websites/servicers and Hong Kong internet users kept failing. Wikipedia, search engines and online messengers were largely unavailable. On December 29th, the Office of the Telecommunications Authority (OFTA) of the Hong Kong Government announced that IDD and roaming calls to Taiwan have resumed to 50% of the normal level, the calls to other Asian countries were slower than normal condition.
The earthquake cut PLDT’s phone service capacity and connectivity by around 40%. The two biggest mobile communications companies in the Philippines (Smart Communications and Globe Telecom) also experienced some international connectivity issues.
In the US, several bloggers and networks had experienced a significant reduction of the volume of spam received after the earthquake. A blogger mentioned “one large network in North America saw their mail from Korea drop by 80% and from China by 99%.”
According to OFTA (Office of the Telecommunications Authority) of Hong Kong Government, among the five cable ships deployed, two arrived at the scene. Unfortunately one of the ships suffered a major fault on December 30th and had to have major repairs in Taiwan – the ship repair was estimated to take about a week, which meant the repair for the cables had to be pushed back.
Before the eventual completion of the cable works, some countries had already created alternative methods to restore their Internet access. For instance, by January 3rd 2007, Singapore’s SingTel had already brought back their Internet access provided by them. SingNet, a subsidiary of SingTel which offers ISP services, announced that “Internet access to services such as gaming and video downloading could experience some delays”. It’s likely that this related to the earthquake.
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