An earthquake measuring 6.6 on the open-ended Richter scale struck Taiwan Monday, the Central Weather Bureau's Seismology Center reported. The quake hit at 10:59 am, at a depth of 20 km, with the epicenter located at sea, 190.4 km northeast of the Lanyu seismic observation station on the outlying island of Lanyu, also known as Orchid Island, and about 300 km off the Batan Islands of the Philippines.

The earthquake was felt throughout Taiwan, with buildings swaying in Taipei for up to 20 seconds, but there were no immediate reports of casualties or damage. Taiwan's TSMC, the world No 1 contract chipmaker, said the quake had no impact on its plants in northern Taiwan. UMC, the world No 2 chipmaker, also reported no impact.

Seismologists said the earthquake was caused by the convergence of the Eurasian and Philippine Sea tectonic plates, and could be considered a normal release of energy. Earthquakes frequently rattle Taiwan, but most are minor and cause little or no damage. However, a magnitude-7.3 earthquake in central Taiwan on September 21, 1999 killed more than 2,300 people.

Philippine authorities forecast little damage after the 10:59 am (0259 GMT) quake struck, but warned people on the coast to watch for a tidal surge. Although it was unlikely to cause casualties or damage, the Pacific Tsunami Warning Center advised that local tsunamis on coastlines within 100 km (60 miles) of the quake's center were possible.

The United States Geological Survey put the quake at a depth of 10 km. Earthquakes occur frequently in Taiwan, which lies on a seismically active stretch of the Pacific basin.

One of Taiwan's worst-recorded quakes occurred in September 1999. Measuring 7.6 on the Richter scale, it killed more than 2,400 people and destroyed or damaged 50,000 buildings.

China Daily/Agencies

(HK Edition 04/27/2010 page4)